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Diffstat (limited to 'src/tr.c')
| -rw-r--r-- | src/tr.c | 1914 |
1 files changed, 1914 insertions, 0 deletions
diff --git a/src/tr.c b/src/tr.c new file mode 100644 index 0000000..6f76507 --- /dev/null +++ b/src/tr.c @@ -0,0 +1,1914 @@ +/* tr -- a filter to translate characters + Copyright (C) 1991-2020 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +/* Written by Jim Meyering */ + +#include <config.h> + +#include <stdio.h> +#include <assert.h> +#include <sys/types.h> +#include <getopt.h> + +#include "system.h" +#include "die.h" +#include "error.h" +#include "fadvise.h" +#include "quote.h" +#include "safe-read.h" +#include "xbinary-io.h" +#include "xstrtol.h" + +/* The official name of this program (e.g., no 'g' prefix). */ +#define PROGRAM_NAME "tr" + +#define AUTHORS proper_name ("Jim Meyering") + +enum { N_CHARS = UCHAR_MAX + 1 }; + +/* An unsigned integer type big enough to hold a repeat count or an + unsigned character. POSIX requires support for repeat counts as + high as 2**31 - 1. Since repeat counts might need to expand to + match the length of an argument string, we need at least size_t to + avoid arbitrary internal limits. It doesn't cost much to use + uintmax_t, though. */ +typedef uintmax_t count; + +/* The value for Spec_list->state that indicates to + get_next that it should initialize the tail pointer. + Its value should be as large as possible to avoid conflict + a valid value for the state field -- and that may be as + large as any valid repeat_count. */ +#define BEGIN_STATE (UINTMAX_MAX - 1) + +/* The value for Spec_list->state that indicates to + get_next that the element pointed to by Spec_list->tail is + being considered for the first time on this pass through the + list -- it indicates that get_next should make any necessary + initializations. */ +#define NEW_ELEMENT (BEGIN_STATE + 1) + +/* The maximum possible repeat count. Due to how the states are + implemented, it can be as much as BEGIN_STATE. */ +#define REPEAT_COUNT_MAXIMUM BEGIN_STATE + +/* The following (but not CC_NO_CLASS) are indices into the array of + valid character class strings. */ +enum Char_class + { + CC_ALNUM = 0, CC_ALPHA = 1, CC_BLANK = 2, CC_CNTRL = 3, + CC_DIGIT = 4, CC_GRAPH = 5, CC_LOWER = 6, CC_PRINT = 7, + CC_PUNCT = 8, CC_SPACE = 9, CC_UPPER = 10, CC_XDIGIT = 11, + CC_NO_CLASS = 9999 + }; + +/* Character class to which a character (returned by get_next) belonged; + but it is set only if the construct from which the character was obtained + was one of the character classes [:upper:] or [:lower:]. The value + is used only when translating and then, only to make sure that upper + and lower class constructs have the same relative positions in string1 + and string2. */ +enum Upper_Lower_class + { + UL_LOWER, + UL_UPPER, + UL_NONE + }; + +/* The type of a List_element. See build_spec_list for more details. */ +enum Range_element_type + { + RE_NORMAL_CHAR, + RE_RANGE, + RE_CHAR_CLASS, + RE_EQUIV_CLASS, + RE_REPEATED_CHAR + }; + +/* One construct in one of tr's argument strings. + For example, consider the POSIX version of the classic tr command: + tr -cs 'a-zA-Z_' '[\n*]' + String1 has 3 constructs, two of which are ranges (a-z and A-Z), + and a single normal character, '_'. String2 has one construct. */ +struct List_element + { + enum Range_element_type type; + struct List_element *next; + union + { + unsigned char normal_char; + struct /* unnamed */ + { + unsigned char first_char; + unsigned char last_char; + } + range; + enum Char_class char_class; + unsigned char equiv_code; + struct /* unnamed */ + { + unsigned char the_repeated_char; + count repeat_count; + } + repeated_char; + } + u; + }; + +/* Each of tr's argument strings is parsed into a form that is easier + to work with: a linked list of constructs (struct List_element). + Each Spec_list structure also encapsulates various attributes of + the corresponding argument string. The attributes are used mainly + to verify that the strings are valid in the context of any options + specified (like -s, -d, or -c). The main exception is the member + 'tail', which is first used to construct the list. After construction, + it is used by get_next to save its state when traversing the list. + The member 'state' serves a similar function. */ +struct Spec_list + { + /* Points to the head of the list of range elements. + The first struct is a dummy; its members are never used. */ + struct List_element *head; + + /* When appending, points to the last element. When traversing via + get_next(), points to the element to process next. Setting + Spec_list.state to the value BEGIN_STATE before calling get_next + signals get_next to initialize tail to point to head->next. */ + struct List_element *tail; + + /* Used to save state between calls to get_next. */ + count state; + + /* Length, in the sense that length ('a-z[:digit:]123abc') + is 42 ( = 26 + 10 + 6). */ + count length; + + /* The number of [c*] and [c*0] constructs that appear in this spec. */ + size_t n_indefinite_repeats; + + /* If n_indefinite_repeats is nonzero, this points to the List_element + corresponding to the last [c*] or [c*0] construct encountered in + this spec. Otherwise it is undefined. */ + struct List_element *indefinite_repeat_element; + + /* True if this spec contains at least one equivalence + class construct e.g. [=c=]. */ + bool has_equiv_class; + + /* True if this spec contains at least one character class + construct. E.g. [:digit:]. */ + bool has_char_class; + + /* True if this spec contains at least one of the character class + constructs (all but upper and lower) that aren't allowed in s2. */ + bool has_restricted_char_class; + }; + +/* A representation for escaped string1 or string2. As a string is parsed, + any backslash-escaped characters (other than octal or \a, \b, \f, \n, + etc.) are marked as such in this structure by setting the corresponding + entry in the ESCAPED vector. */ +struct E_string +{ + char *s; + bool *escaped; + size_t len; +}; + +/* Return nonzero if the Ith character of escaped string ES matches C + and is not escaped itself. */ +static inline bool +es_match (struct E_string const *es, size_t i, char c) +{ + return es->s[i] == c && !es->escaped[i]; +} + +/* When true, each sequence in the input of a repeated character + (call it c) is replaced (in the output) by a single occurrence of c + for every c in the squeeze set. */ +static bool squeeze_repeats = false; + +/* When true, removes characters in the delete set from input. */ +static bool delete = false; + +/* Use the complement of set1 in place of set1. */ +static bool complement = false; + +/* When tr is performing translation and string1 is longer than string2, + POSIX says that the result is unspecified. That gives the implementor + of a POSIX conforming version of tr two reasonable choices for the + semantics of this case. + + * The BSD tr pads string2 to the length of string1 by + repeating the last character in string2. + + * System V tr ignores characters in string1 that have no + corresponding character in string2. That is, string1 is effectively + truncated to the length of string2. + + When nonzero, this flag causes GNU tr to imitate the behavior + of System V tr when translating with string1 longer than string2. + The default is to emulate BSD tr. This flag is ignored in modes where + no translation is performed. Emulating the System V tr + in this exceptional case causes the relatively common BSD idiom: + + tr -cs A-Za-z0-9 '\012' + + to break (it would convert only zero bytes, rather than all + non-alphanumerics, to newlines). + + WARNING: This switch does not provide general BSD or System V + compatibility. For example, it doesn't disable the interpretation + of the POSIX constructs [:alpha:], [=c=], and [c*10], so if by + some unfortunate coincidence you use such constructs in scripts + expecting to use some other version of tr, the scripts will break. */ +static bool truncate_set1 = false; + +/* An alias for (!delete && non_option_args == 2). + It is set in main and used there and in validate(). */ +static bool translating; + +static char io_buf[BUFSIZ]; + +static char const *const char_class_name[] = +{ + "alnum", "alpha", "blank", "cntrl", "digit", "graph", + "lower", "print", "punct", "space", "upper", "xdigit" +}; + +/* Array of boolean values. A character 'c' is a member of the + squeeze set if and only if in_squeeze_set[c] is true. The squeeze + set is defined by the last (possibly, the only) string argument + on the command line when the squeeze option is given. */ +static bool in_squeeze_set[N_CHARS]; + +/* Array of boolean values. A character 'c' is a member of the + delete set if and only if in_delete_set[c] is true. The delete + set is defined by the first (or only) string argument on the + command line when the delete option is given. */ +static bool in_delete_set[N_CHARS]; + +/* Array of character values defining the translation (if any) that + tr is to perform. Translation is performed only when there are + two specification strings and the delete switch is not given. */ +static char xlate[N_CHARS]; + +static struct option const long_options[] = +{ + {"complement", no_argument, NULL, 'c'}, + {"delete", no_argument, NULL, 'd'}, + {"squeeze-repeats", no_argument, NULL, 's'}, + {"truncate-set1", no_argument, NULL, 't'}, + {GETOPT_HELP_OPTION_DECL}, + {GETOPT_VERSION_OPTION_DECL}, + {NULL, 0, NULL, 0} +}; + +void +usage (int status) +{ + if (status != EXIT_SUCCESS) + emit_try_help (); + else + { + printf (_("\ +Usage: %s [OPTION]... SET1 [SET2]\n\ +"), + program_name); + fputs (_("\ +Translate, squeeze, and/or delete characters from standard input,\n\ +writing to standard output.\n\ +\n\ + -c, -C, --complement use the complement of SET1\n\ + -d, --delete delete characters in SET1, do not translate\n\ + -s, --squeeze-repeats replace each sequence of a repeated character\n\ + that is listed in the last specified SET,\n\ + with a single occurrence of that character\n\ + -t, --truncate-set1 first truncate SET1 to length of SET2\n\ +"), stdout); + fputs (HELP_OPTION_DESCRIPTION, stdout); + fputs (VERSION_OPTION_DESCRIPTION, stdout); + fputs (_("\ +\n\ +SETs are specified as strings of characters. Most represent themselves.\n\ +Interpreted sequences are:\n\ +\n\ + \\NNN character with octal value NNN (1 to 3 octal digits)\n\ + \\\\ backslash\n\ + \\a audible BEL\n\ + \\b backspace\n\ + \\f form feed\n\ + \\n new line\n\ + \\r return\n\ + \\t horizontal tab\n\ +"), stdout); + fputs (_("\ + \\v vertical tab\n\ + CHAR1-CHAR2 all characters from CHAR1 to CHAR2 in ascending order\n\ + [CHAR*] in SET2, copies of CHAR until length of SET1\n\ + [CHAR*REPEAT] REPEAT copies of CHAR, REPEAT octal if starting with 0\n\ + [:alnum:] all letters and digits\n\ + [:alpha:] all letters\n\ + [:blank:] all horizontal whitespace\n\ + [:cntrl:] all control characters\n\ + [:digit:] all digits\n\ +"), stdout); + fputs (_("\ + [:graph:] all printable characters, not including space\n\ + [:lower:] all lower case letters\n\ + [:print:] all printable characters, including space\n\ + [:punct:] all punctuation characters\n\ + [:space:] all horizontal or vertical whitespace\n\ + [:upper:] all upper case letters\n\ + [:xdigit:] all hexadecimal digits\n\ + [=CHAR=] all characters which are equivalent to CHAR\n\ +"), stdout); + fputs (_("\ +\n\ +Translation occurs if -d is not given and both SET1 and SET2 appear.\n\ +-t may be used only when translating. SET2 is extended to length of\n\ +SET1 by repeating its last character as necessary. Excess characters\n\ +of SET2 are ignored. Only [:lower:] and [:upper:] are guaranteed to\n\ +expand in ascending order; used in SET2 while translating, they may\n\ +only be used in pairs to specify case conversion. -s uses the last\n\ +specified SET, and occurs after translation or deletion.\n\ +"), stdout); + emit_ancillary_info (PROGRAM_NAME); + } + exit (status); +} + +/* Return nonzero if the character C is a member of the + equivalence class containing the character EQUIV_CLASS. */ + +static inline bool +is_equiv_class_member (unsigned char equiv_class, unsigned char c) +{ + return (equiv_class == c); +} + +/* Return true if the character C is a member of the + character class CHAR_CLASS. */ + +static bool _GL_ATTRIBUTE_PURE +is_char_class_member (enum Char_class char_class, unsigned char c) +{ + int result; + + switch (char_class) + { + case CC_ALNUM: + result = isalnum (c); + break; + case CC_ALPHA: + result = isalpha (c); + break; + case CC_BLANK: + result = isblank (c); + break; + case CC_CNTRL: + result = iscntrl (c); + break; + case CC_DIGIT: + result = isdigit (c); + break; + case CC_GRAPH: + result = isgraph (c); + break; + case CC_LOWER: + result = islower (c); + break; + case CC_PRINT: + result = isprint (c); + break; + case CC_PUNCT: + result = ispunct (c); + break; + case CC_SPACE: + result = isspace (c); + break; + case CC_UPPER: + result = isupper (c); + break; + case CC_XDIGIT: + result = isxdigit (c); + break; + default: + abort (); + } + + return !! result; +} + +static void +es_free (struct E_string *es) +{ + free (es->s); + free (es->escaped); +} + +/* Perform the first pass over each range-spec argument S, converting all + \c and \ddd escapes to their one-byte representations. If an invalid + quote sequence is found print an error message and return false; + Otherwise set *ES to the resulting string and return true. + The resulting array of characters may contain zero-bytes; + however, on input, S is assumed to be null-terminated, and hence + cannot contain actual (non-escaped) zero bytes. */ + +static bool +unquote (char const *s, struct E_string *es) +{ + size_t len = strlen (s); + + es->s = xmalloc (len); + es->escaped = xcalloc (len, sizeof es->escaped[0]); + + unsigned int j = 0; + for (unsigned int i = 0; s[i]; i++) + { + unsigned char c; + int oct_digit; + + switch (s[i]) + { + case '\\': + es->escaped[j] = true; + switch (s[i + 1]) + { + case '\\': + c = '\\'; + break; + case 'a': + c = '\a'; + break; + case 'b': + c = '\b'; + break; + case 'f': + c = '\f'; + break; + case 'n': + c = '\n'; + break; + case 'r': + c = '\r'; + break; + case 't': + c = '\t'; + break; + case 'v': + c = '\v'; + break; + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + c = s[i + 1] - '0'; + oct_digit = s[i + 2] - '0'; + if (0 <= oct_digit && oct_digit <= 7) + { + c = 8 * c + oct_digit; + ++i; + oct_digit = s[i + 2] - '0'; + if (0 <= oct_digit && oct_digit <= 7) + { + if (8 * c + oct_digit < N_CHARS) + { + c = 8 * c + oct_digit; + ++i; + } + else + { + /* A 3-digit octal number larger than \377 won't + fit in 8 bits. So we stop when adding the + next digit would put us over the limit and + give a warning about the ambiguity. POSIX + isn't clear on this, and we interpret this + lack of clarity as meaning the resulting behavior + is undefined, which means we're allowed to issue + a warning. */ + error (0, 0, _("warning: the ambiguous octal escape\ + \\%c%c%c is being\n\tinterpreted as the 2-byte sequence \\0%c%c, %c"), + s[i], s[i + 1], s[i + 2], + s[i], s[i + 1], s[i + 2]); + } + } + } + break; + case '\0': + error (0, 0, _("warning: an unescaped backslash " + "at end of string is not portable")); + /* POSIX is not clear about this. */ + es->escaped[j] = false; + i--; + c = '\\'; + break; + default: + c = s[i + 1]; + break; + } + ++i; + es->s[j++] = c; + break; + default: + es->s[j++] = s[i]; + break; + } + } + es->len = j; + return true; +} + +/* If CLASS_STR is a valid character class string, return its index + in the global char_class_name array. Otherwise, return CC_NO_CLASS. */ + +static enum Char_class _GL_ATTRIBUTE_PURE +look_up_char_class (char const *class_str, size_t len) +{ + enum Char_class i; + + for (i = 0; i < ARRAY_CARDINALITY (char_class_name); i++) + if (STREQ_LEN (class_str, char_class_name[i], len) + && strlen (char_class_name[i]) == len) + return i; + return CC_NO_CLASS; +} + +/* Return a newly allocated string with a printable version of C. + This function is used solely for formatting error messages. */ + +static char * +make_printable_char (unsigned char c) +{ + char *buf = xmalloc (5); + + if (isprint (c)) + { + buf[0] = c; + buf[1] = '\0'; + } + else + { + sprintf (buf, "\\%03o", c); + } + return buf; +} + +/* Return a newly allocated copy of S which is suitable for printing. + LEN is the number of characters in S. Most non-printing + (isprint) characters are represented by a backslash followed by + 3 octal digits. However, the characters represented by \c escapes + where c is one of [abfnrtv] are represented by their 2-character \c + sequences. This function is used solely for printing error messages. */ + +static char * +make_printable_str (char const *s, size_t len) +{ + /* Worst case is that every character expands to a backslash + followed by a 3-character octal escape sequence. */ + char *printable_buf = xnmalloc (len + 1, 4); + char *p = printable_buf; + + for (size_t i = 0; i < len; i++) + { + char buf[5]; + char const *tmp = NULL; + unsigned char c = s[i]; + + switch (c) + { + case '\\': + tmp = "\\"; + break; + case '\a': + tmp = "\\a"; + break; + case '\b': + tmp = "\\b"; + break; + case '\f': + tmp = "\\f"; + break; + case '\n': + tmp = "\\n"; + break; + case '\r': + tmp = "\\r"; + break; + case '\t': + tmp = "\\t"; + break; + case '\v': + tmp = "\\v"; + break; + default: + if (isprint (c)) + { + buf[0] = c; + buf[1] = '\0'; + } + else + sprintf (buf, "\\%03o", c); + tmp = buf; + break; + } + p = stpcpy (p, tmp); + } + return printable_buf; +} + +/* Append a newly allocated structure representing a + character C to the specification list LIST. */ + +static void +append_normal_char (struct Spec_list *list, unsigned char c) +{ + struct List_element *new = xmalloc (sizeof *new); + new->next = NULL; + new->type = RE_NORMAL_CHAR; + new->u.normal_char = c; + assert (list->tail); + list->tail->next = new; + list->tail = new; +} + +/* Append a newly allocated structure representing the range + of characters from FIRST to LAST to the specification list LIST. + Return false if LAST precedes FIRST in the collating sequence, + true otherwise. This means that '[c-c]' is acceptable. */ + +static bool +append_range (struct Spec_list *list, unsigned char first, unsigned char last) +{ + if (last < first) + { + char *tmp1 = make_printable_char (first); + char *tmp2 = make_printable_char (last); + + error (0, 0, + _("range-endpoints of '%s-%s' are in reverse collating sequence order"), + tmp1, tmp2); + free (tmp1); + free (tmp2); + return false; + } + struct List_element *new = xmalloc (sizeof *new); + new->next = NULL; + new->type = RE_RANGE; + new->u.range.first_char = first; + new->u.range.last_char = last; + assert (list->tail); + list->tail->next = new; + list->tail = new; + return true; +} + +/* If CHAR_CLASS_STR is a valid character class string, append a + newly allocated structure representing that character class to the end + of the specification list LIST and return true. If CHAR_CLASS_STR is not + a valid string return false. */ + +static bool +append_char_class (struct Spec_list *list, + char const *char_class_str, size_t len) +{ + enum Char_class char_class = look_up_char_class (char_class_str, len); + if (char_class == CC_NO_CLASS) + return false; + struct List_element *new = xmalloc (sizeof *new); + new->next = NULL; + new->type = RE_CHAR_CLASS; + new->u.char_class = char_class; + assert (list->tail); + list->tail->next = new; + list->tail = new; + return true; +} + +/* Append a newly allocated structure representing a [c*n] + repeated character construct to the specification list LIST. + THE_CHAR is the single character to be repeated, and REPEAT_COUNT + is a non-negative repeat count. */ + +static void +append_repeated_char (struct Spec_list *list, unsigned char the_char, + count repeat_count) +{ + struct List_element *new = xmalloc (sizeof *new); + new->next = NULL; + new->type = RE_REPEATED_CHAR; + new->u.repeated_char.the_repeated_char = the_char; + new->u.repeated_char.repeat_count = repeat_count; + assert (list->tail); + list->tail->next = new; + list->tail = new; +} + +/* Given a string, EQUIV_CLASS_STR, from a [=str=] context and + the length of that string, LEN, if LEN is exactly one, append + a newly allocated structure representing the specified + equivalence class to the specification list, LIST and return true. + If LEN is not 1, return false. */ + +static bool +append_equiv_class (struct Spec_list *list, + char const *equiv_class_str, size_t len) +{ + if (len != 1) + return false; + + struct List_element *new = xmalloc (sizeof *new); + new->next = NULL; + new->type = RE_EQUIV_CLASS; + new->u.equiv_code = *equiv_class_str; + assert (list->tail); + list->tail->next = new; + list->tail = new; + return true; +} + +/* Search forward starting at START_IDX for the 2-char sequence + (PRE_BRACKET_CHAR,']') in the string P of length P_LEN. If such + a sequence is found, set *RESULT_IDX to the index of the first + character and return true. Otherwise return false. P may contain + zero bytes. */ + +static bool +find_closing_delim (const struct E_string *es, size_t start_idx, + char pre_bracket_char, size_t *result_idx) +{ + for (size_t i = start_idx; i < es->len - 1; i++) + if (es->s[i] == pre_bracket_char && es->s[i + 1] == ']' + && !es->escaped[i] && !es->escaped[i + 1]) + { + *result_idx = i; + return true; + } + return false; +} + +/* Parse the bracketed repeat-char syntax. If the P_LEN characters + beginning with P[ START_IDX ] comprise a valid [c*n] construct, + then set *CHAR_TO_REPEAT, *REPEAT_COUNT, and *CLOSING_BRACKET_IDX + and return zero. If the second character following + the opening bracket is not '*' or if no closing bracket can be + found, return -1. If a closing bracket is found and the + second char is '*', but the string between the '*' and ']' isn't + empty, an octal number, or a decimal number, print an error message + and return -2. */ + +static int +find_bracketed_repeat (const struct E_string *es, size_t start_idx, + unsigned char *char_to_repeat, count *repeat_count, + size_t *closing_bracket_idx) +{ + assert (start_idx + 1 < es->len); + if (!es_match (es, start_idx + 1, '*')) + return -1; + + for (size_t i = start_idx + 2; i < es->len && !es->escaped[i]; i++) + { + if (es->s[i] == ']') + { + size_t digit_str_len = i - start_idx - 2; + + *char_to_repeat = es->s[start_idx]; + if (digit_str_len == 0) + { + /* We've matched [c*] -- no explicit repeat count. */ + *repeat_count = 0; + } + else + { + /* Here, we have found [c*s] where s should be a string + of octal (if it starts with '0') or decimal digits. */ + char const *digit_str = &es->s[start_idx + 2]; + char *d_end; + if ((xstrtoumax (digit_str, &d_end, *digit_str == '0' ? 8 : 10, + repeat_count, NULL) + != LONGINT_OK) + || REPEAT_COUNT_MAXIMUM < *repeat_count + || digit_str + digit_str_len != d_end) + { + char *tmp = make_printable_str (digit_str, digit_str_len); + error (0, 0, + _("invalid repeat count %s in [c*n] construct"), + quote (tmp)); + free (tmp); + return -2; + } + } + *closing_bracket_idx = i; + return 0; + } + } + return -1; /* No bracket found. */ +} + +/* Return true if the string at ES->s[IDX] matches the regular + expression '\*[0-9]*\]', false otherwise. The string does not + match if any of its characters are escaped. */ + +static bool _GL_ATTRIBUTE_PURE +star_digits_closebracket (const struct E_string *es, size_t idx) +{ + if (!es_match (es, idx, '*')) + return false; + + for (size_t i = idx + 1; i < es->len; i++) + if (!ISDIGIT (to_uchar (es->s[i])) || es->escaped[i]) + return es_match (es, i, ']'); + return false; +} + +/* Convert string UNESCAPED_STRING (which has been preprocessed to + convert backslash-escape sequences) of length LEN characters into + a linked list of the following 5 types of constructs: + - [:str:] Character class where 'str' is one of the 12 valid strings. + - [=c=] Equivalence class where 'c' is any single character. + - [c*n] Repeat the single character 'c' 'n' times. n may be omitted. + However, if 'n' is present, it must be a non-negative octal or + decimal integer. + - r-s Range of characters from 'r' to 's'. The second endpoint must + not precede the first in the current collating sequence. + - c Any other character is interpreted as itself. */ + +static bool +build_spec_list (const struct E_string *es, struct Spec_list *result) +{ + char const *p = es->s; + + /* The main for-loop below recognizes the 4 multi-character constructs. + A character that matches (in its context) none of the multi-character + constructs is classified as 'normal'. Since all multi-character + constructs have at least 3 characters, any strings of length 2 or + less are composed solely of normal characters. Hence, the index of + the outer for-loop runs only as far as LEN-2. */ + size_t i; + for (i = 0; i + 2 < es->len; /* empty */) + { + if (es_match (es, i, '[')) + { + bool matched_multi_char_construct; + size_t closing_bracket_idx; + unsigned char char_to_repeat; + count repeat_count; + int err; + + matched_multi_char_construct = true; + if (es_match (es, i + 1, ':') || es_match (es, i + 1, '=')) + { + size_t closing_delim_idx; + + if (find_closing_delim (es, i + 2, p[i + 1], &closing_delim_idx)) + { + size_t opnd_str_len = closing_delim_idx - 1 - (i + 2) + 1; + char const *opnd_str = p + i + 2; + + if (opnd_str_len == 0) + { + if (p[i + 1] == ':') + error (0, 0, _("missing character class name '[::]'")); + else + error (0, 0, + _("missing equivalence class character '[==]'")); + return false; + } + + if (p[i + 1] == ':') + { + /* FIXME: big comment. */ + if (!append_char_class (result, opnd_str, opnd_str_len)) + { + if (star_digits_closebracket (es, i + 2)) + goto try_bracketed_repeat; + else + { + char *tmp = make_printable_str (opnd_str, + opnd_str_len); + error (0, 0, _("invalid character class %s"), + quote (tmp)); + free (tmp); + return false; + } + } + } + else + { + /* FIXME: big comment. */ + if (!append_equiv_class (result, opnd_str, opnd_str_len)) + { + if (star_digits_closebracket (es, i + 2)) + goto try_bracketed_repeat; + else + { + char *tmp = make_printable_str (opnd_str, + opnd_str_len); + error (0, 0, + _("%s: equivalence class operand must be a single character"), + tmp); + free (tmp); + return false; + } + } + } + + i = closing_delim_idx + 2; + continue; + } + /* Else fall through. This could be [:*] or [=*]. */ + } + + try_bracketed_repeat: + + /* Determine whether this is a bracketed repeat range + matching the RE \[.\*(dec_or_oct_number)?\]. */ + err = find_bracketed_repeat (es, i + 1, &char_to_repeat, + &repeat_count, + &closing_bracket_idx); + if (err == 0) + { + append_repeated_char (result, char_to_repeat, repeat_count); + i = closing_bracket_idx + 1; + } + else if (err == -1) + { + matched_multi_char_construct = false; + } + else + { + /* Found a string that looked like [c*n] but the + numeric part was invalid. */ + return false; + } + + if (matched_multi_char_construct) + continue; + + /* We reach this point if P does not match [:str:], [=c=], + [c*n], or [c*]. Now, see if P looks like a range '[-c' + (from '[' to 'c'). */ + } + + /* Look ahead one char for ranges like a-z. */ + if (es_match (es, i + 1, '-')) + { + if (!append_range (result, p[i], p[i + 2])) + return false; + i += 3; + } + else + { + append_normal_char (result, p[i]); + ++i; + } + } + + /* Now handle the (2 or fewer) remaining characters p[i]..p[es->len - 1]. */ + for (; i < es->len; i++) + append_normal_char (result, p[i]); + + return true; +} + +/* Advance past the current construct. + S->tail must be non-NULL. */ +static void +skip_construct (struct Spec_list *s) +{ + s->tail = s->tail->next; + s->state = NEW_ELEMENT; +} + +/* Given a Spec_list S (with its saved state implicit in the values + of its members 'tail' and 'state'), return the next single character + in the expansion of S's constructs. If the last character of S was + returned on the previous call or if S was empty, this function + returns -1. For example, successive calls to get_next where S + represents the spec-string 'a-d[y*3]' will return the sequence + of values a, b, c, d, y, y, y, -1. Finally, if the construct from + which the returned character comes is [:upper:] or [:lower:], the + parameter CLASS is given a value to indicate which it was. Otherwise + CLASS is set to UL_NONE. This value is used only when constructing + the translation table to verify that any occurrences of upper and + lower class constructs in the spec-strings appear in the same relative + positions. */ + +static int +get_next (struct Spec_list *s, enum Upper_Lower_class *class) +{ + struct List_element *p; + int return_val; + int i; + + if (class) + *class = UL_NONE; + + if (s->state == BEGIN_STATE) + { + s->tail = s->head->next; + s->state = NEW_ELEMENT; + } + + p = s->tail; + if (p == NULL) + return -1; + + switch (p->type) + { + case RE_NORMAL_CHAR: + return_val = p->u.normal_char; + s->state = NEW_ELEMENT; + s->tail = p->next; + break; + + case RE_RANGE: + if (s->state == NEW_ELEMENT) + s->state = p->u.range.first_char; + else + ++(s->state); + return_val = s->state; + if (s->state == p->u.range.last_char) + { + s->tail = p->next; + s->state = NEW_ELEMENT; + } + break; + + case RE_CHAR_CLASS: + if (class) + { + switch (p->u.char_class) + { + case CC_LOWER: + *class = UL_LOWER; + break; + case CC_UPPER: + *class = UL_UPPER; + break; + default: + break; + } + } + + if (s->state == NEW_ELEMENT) + { + for (i = 0; i < N_CHARS; i++) + if (is_char_class_member (p->u.char_class, i)) + break; + assert (i < N_CHARS); + s->state = i; + } + assert (is_char_class_member (p->u.char_class, s->state)); + return_val = s->state; + for (i = s->state + 1; i < N_CHARS; i++) + if (is_char_class_member (p->u.char_class, i)) + break; + if (i < N_CHARS) + s->state = i; + else + { + s->tail = p->next; + s->state = NEW_ELEMENT; + } + break; + + case RE_EQUIV_CLASS: + /* FIXME: this assumes that each character is alone in its own + equivalence class (which appears to be correct for my + LC_COLLATE. But I don't know of any function that allows + one to determine a character's equivalence class. */ + + return_val = p->u.equiv_code; + s->state = NEW_ELEMENT; + s->tail = p->next; + break; + + case RE_REPEATED_CHAR: + /* Here, a repeat count of n == 0 means don't repeat at all. */ + if (p->u.repeated_char.repeat_count == 0) + { + s->tail = p->next; + s->state = NEW_ELEMENT; + return_val = get_next (s, class); + } + else + { + if (s->state == NEW_ELEMENT) + { + s->state = 0; + } + ++(s->state); + return_val = p->u.repeated_char.the_repeated_char; + if (s->state == p->u.repeated_char.repeat_count) + { + s->tail = p->next; + s->state = NEW_ELEMENT; + } + } + break; + + default: + abort (); + } + + return return_val; +} + +/* This is a minor kludge. This function is called from + get_spec_stats to determine the cardinality of a set derived + from a complemented string. It's a kludge in that some of the + same operations are (duplicated) performed in set_initialize. */ + +static int +card_of_complement (struct Spec_list *s) +{ + int c; + int cardinality = N_CHARS; + bool in_set[N_CHARS] = { 0, }; + + s->state = BEGIN_STATE; + while ((c = get_next (s, NULL)) != -1) + { + cardinality -= (!in_set[c]); + in_set[c] = true; + } + return cardinality; +} + +/* Discard the lengths associated with a case conversion, + as using the actual number of upper or lower case characters + is problematic when they don't match in some locales. + Also ensure the case conversion classes in string2 are + aligned correctly with those in string1. + Note POSIX says the behavior of 'tr "[:upper:]" "[:upper:]"' + is undefined. Therefore we allow it (unlike Solaris) + and treat it as a no-op. */ + +static void +validate_case_classes (struct Spec_list *s1, struct Spec_list *s2) +{ + size_t n_upper = 0; + size_t n_lower = 0; + int c1 = 0; + int c2 = 0; + count old_s1_len = s1->length; + count old_s2_len = s2->length; + struct List_element *s1_tail = s1->tail; + struct List_element *s2_tail = s2->tail; + bool s1_new_element = true; + bool s2_new_element = true; + + if (!s2->has_char_class) + return; + + for (int i = 0; i < N_CHARS; i++) + { + if (isupper (i)) + n_upper++; + if (islower (i)) + n_lower++; + } + + s1->state = BEGIN_STATE; + s2->state = BEGIN_STATE; + + while (c1 != -1 && c2 != -1) + { + enum Upper_Lower_class class_s1, class_s2; + + c1 = get_next (s1, &class_s1); + c2 = get_next (s2, &class_s2); + + /* If c2 transitions to a new case class, then + c1 must also transition at the same time. */ + if (s2_new_element && class_s2 != UL_NONE + && !(s1_new_element && class_s1 != UL_NONE)) + die (EXIT_FAILURE, 0, + _("misaligned [:upper:] and/or [:lower:] construct")); + + /* If case converting, quickly skip over the elements. */ + if (class_s2 != UL_NONE) + { + skip_construct (s1); + skip_construct (s2); + /* Discount insignificant/problematic lengths. */ + s1->length -= (class_s1 == UL_UPPER ? n_upper : n_lower) - 1; + s2->length -= (class_s2 == UL_UPPER ? n_upper : n_lower) - 1; + } + + s1_new_element = s1->state == NEW_ELEMENT; /* Next element is new. */ + s2_new_element = s2->state == NEW_ELEMENT; /* Next element is new. */ + } + + assert (old_s1_len >= s1->length && old_s2_len >= s2->length); + + s1->tail = s1_tail; + s2->tail = s2_tail; +} + +/* Gather statistics about the spec-list S in preparation for the tests + in validate that determine the consistency of the specs. This function + is called at most twice; once for string1, and again for any string2. + LEN_S1 < 0 indicates that this is the first call and that S represents + string1. When LEN_S1 >= 0, it is the length of the expansion of the + constructs in string1, and we can use its value to resolve any + indefinite repeat construct in S (which represents string2). Hence, + this function has the side-effect that it converts a valid [c*] + construct in string2 to [c*n] where n is large enough (or 0) to give + string2 the same length as string1. For example, with the command + tr a-z 'A[\n*]Z' on the second call to get_spec_stats, LEN_S1 would + be 26 and S (representing string2) would be converted to 'A[\n*24]Z'. */ + +static void +get_spec_stats (struct Spec_list *s) +{ + struct List_element *p; + count length = 0; + + s->n_indefinite_repeats = 0; + s->has_equiv_class = false; + s->has_restricted_char_class = false; + s->has_char_class = false; + for (p = s->head->next; p; p = p->next) + { + count len = 0; + count new_length; + + switch (p->type) + { + case RE_NORMAL_CHAR: + len = 1; + break; + + case RE_RANGE: + assert (p->u.range.last_char >= p->u.range.first_char); + len = p->u.range.last_char - p->u.range.first_char + 1; + break; + + case RE_CHAR_CLASS: + s->has_char_class = true; + for (int i = 0; i < N_CHARS; i++) + if (is_char_class_member (p->u.char_class, i)) + ++len; + switch (p->u.char_class) + { + case CC_UPPER: + case CC_LOWER: + break; + default: + s->has_restricted_char_class = true; + break; + } + break; + + case RE_EQUIV_CLASS: + for (int i = 0; i < N_CHARS; i++) + if (is_equiv_class_member (p->u.equiv_code, i)) + ++len; + s->has_equiv_class = true; + break; + + case RE_REPEATED_CHAR: + if (p->u.repeated_char.repeat_count > 0) + len = p->u.repeated_char.repeat_count; + else + { + s->indefinite_repeat_element = p; + ++(s->n_indefinite_repeats); + } + break; + + default: + abort (); + } + + /* Check for arithmetic overflow in computing length. Also, reject + any length greater than the maximum repeat count, in case the + length is later used to compute the repeat count for an + indefinite element. */ + new_length = length + len; + if (! (length <= new_length && new_length <= REPEAT_COUNT_MAXIMUM)) + die (EXIT_FAILURE, 0, _("too many characters in set")); + length = new_length; + } + + s->length = length; +} + +static void +get_s1_spec_stats (struct Spec_list *s1) +{ + get_spec_stats (s1); + if (complement) + s1->length = card_of_complement (s1); +} + +static void +get_s2_spec_stats (struct Spec_list *s2, count len_s1) +{ + get_spec_stats (s2); + if (len_s1 >= s2->length && s2->n_indefinite_repeats == 1) + { + s2->indefinite_repeat_element->u.repeated_char.repeat_count = + len_s1 - s2->length; + s2->length = len_s1; + } +} + +static void +spec_init (struct Spec_list *spec_list) +{ + struct List_element *new = xmalloc (sizeof *new); + spec_list->head = spec_list->tail = new; + spec_list->head->next = NULL; +} + +/* This function makes two passes over the argument string S. The first + one converts all \c and \ddd escapes to their one-byte representations. + The second constructs a linked specification list, SPEC_LIST, of the + characters and constructs that comprise the argument string. If either + of these passes detects an error, this function returns false. */ + +static bool +parse_str (char const *s, struct Spec_list *spec_list) +{ + struct E_string es; + bool ok = unquote (s, &es) && build_spec_list (&es, spec_list); + es_free (&es); + return ok; +} + +/* Given two specification lists, S1 and S2, and assuming that + S1->length > S2->length, append a single [c*n] element to S2 where c + is the last character in the expansion of S2 and n is the difference + between the two lengths. + Upon successful completion, S2->length is set to S1->length. The only + way this function can fail to make S2 as long as S1 is when S2 has + zero-length, since in that case, there is no last character to repeat. + So S2->length is required to be at least 1. */ + +static void +string2_extend (const struct Spec_list *s1, struct Spec_list *s2) +{ + struct List_element *p; + unsigned char char_to_repeat; + + assert (translating); + assert (s1->length > s2->length); + assert (s2->length > 0); + + p = s2->tail; + switch (p->type) + { + case RE_NORMAL_CHAR: + char_to_repeat = p->u.normal_char; + break; + case RE_RANGE: + char_to_repeat = p->u.range.last_char; + break; + case RE_CHAR_CLASS: + /* Note BSD allows extending of classes in string2. For example: + tr '[:upper:]0-9' '[:lower:]' + That's not portable however, contradicts POSIX and is dependent + on your collating sequence. */ + die (EXIT_FAILURE, 0, + _("when translating with string1 longer than string2,\nthe\ + latter string must not end with a character class")); + + case RE_REPEATED_CHAR: + char_to_repeat = p->u.repeated_char.the_repeated_char; + break; + + case RE_EQUIV_CLASS: + /* This shouldn't happen, because validate exits with an error + if it finds an equiv class in string2 when translating. */ + abort (); + + default: + abort (); + } + + append_repeated_char (s2, char_to_repeat, s1->length - s2->length); + s2->length = s1->length; +} + +/* Return true if S is a non-empty list in which exactly one + character (but potentially, many instances of it) appears. + E.g., [X*] or xxxxxxxx. */ + +static bool +homogeneous_spec_list (struct Spec_list *s) +{ + int b, c; + + s->state = BEGIN_STATE; + + if ((b = get_next (s, NULL)) == -1) + return false; + + while ((c = get_next (s, NULL)) != -1) + if (c != b) + return false; + + return true; +} + +/* Die with an error message if S1 and S2 describe strings that + are not valid with the given command line switches. + A side effect of this function is that if a valid [c*] or + [c*0] construct appears in string2, it is converted to [c*n] + with a value for n that makes s2->length == s1->length. By + the same token, if the --truncate-set1 option is not + given, S2 may be extended. */ + +static void +validate (struct Spec_list *s1, struct Spec_list *s2) +{ + get_s1_spec_stats (s1); + if (s1->n_indefinite_repeats > 0) + { + die (EXIT_FAILURE, 0, + _("the [c*] repeat construct may not appear in string1")); + } + + if (s2) + { + get_s2_spec_stats (s2, s1->length); + + if (s2->n_indefinite_repeats > 1) + { + die (EXIT_FAILURE, 0, + _("only one [c*] repeat construct may appear in string2")); + } + + if (translating) + { + if (s2->has_equiv_class) + { + die (EXIT_FAILURE, 0, + _("[=c=] expressions may not appear in string2\ + when translating")); + } + + if (s2->has_restricted_char_class) + { + die (EXIT_FAILURE, 0, + _("when translating, the only character classes that may\ + appear in\nstring2 are 'upper' and 'lower'")); + } + + validate_case_classes (s1, s2); + + if (s1->length > s2->length) + { + if (!truncate_set1) + { + /* string2 must be non-empty unless --truncate-set1 is + given or string1 is empty. */ + + if (s2->length == 0) + die (EXIT_FAILURE, 0, + _("when not truncating set1, string2 must be non-empty")); + string2_extend (s1, s2); + } + } + + if (complement && s1->has_char_class + && ! (s2->length == s1->length && homogeneous_spec_list (s2))) + { + die (EXIT_FAILURE, 0, + _("when translating with complemented character classes,\ +\nstring2 must map all characters in the domain to one")); + } + } + else + /* Not translating. */ + { + if (s2->n_indefinite_repeats > 0) + die (EXIT_FAILURE, 0, + _("the [c*] construct may appear in string2 only\ + when translating")); + } + } +} + +/* Read buffers of SIZE bytes via the function READER (if READER is + NULL, read from stdin) until EOF. When non-NULL, READER is either + read_and_delete or read_and_xlate. After each buffer is read, it is + processed and written to stdout. The buffers are processed so that + multiple consecutive occurrences of the same character in the input + stream are replaced by a single occurrence of that character if the + character is in the squeeze set. */ + +static void +squeeze_filter (char *buf, size_t size, size_t (*reader) (char *, size_t)) +{ + /* A value distinct from any character that may have been stored in a + buffer as the result of a block-read in the function squeeze_filter. */ + const int NOT_A_CHAR = INT_MAX; + + int char_to_squeeze = NOT_A_CHAR; + size_t i = 0; + size_t nr = 0; + + while (true) + { + if (i >= nr) + { + nr = reader (buf, size); + if (nr == 0) + break; + i = 0; + } + + size_t begin = i; + + if (char_to_squeeze == NOT_A_CHAR) + { + size_t out_len; + /* Here, by being a little tricky, we can get a significant + performance increase in most cases when the input is + reasonably large. Since tr will modify the input only + if two consecutive (and identical) input characters are + in the squeeze set, we can step by two through the data + when searching for a character in the squeeze set. This + means there may be a little more work in a few cases and + perhaps twice as much work in the worst cases where most + of the input is removed by squeezing repeats. But most + uses of this functionality seem to remove less than 20-30% + of the input. */ + for (; i < nr && !in_squeeze_set[to_uchar (buf[i])]; i += 2) + continue; + + /* There is a special case when i == nr and we've just + skipped a character (the last one in buf) that is in + the squeeze set. */ + if (i == nr && in_squeeze_set[to_uchar (buf[i - 1])]) + --i; + + if (i >= nr) + out_len = nr - begin; + else + { + char_to_squeeze = buf[i]; + /* We're about to output buf[begin..i]. */ + out_len = i - begin + 1; + + /* But since we stepped by 2 in the loop above, + out_len may be one too large. */ + if (i > 0 && buf[i - 1] == char_to_squeeze) + --out_len; + + /* Advance i to the index of first character to be + considered when looking for a char different from + char_to_squeeze. */ + ++i; + } + if (out_len > 0 + && fwrite (&buf[begin], 1, out_len, stdout) != out_len) + die (EXIT_FAILURE, errno, _("write error")); + } + + if (char_to_squeeze != NOT_A_CHAR) + { + /* Advance i to index of first char != char_to_squeeze + (or to nr if all the rest of the characters in this + buffer are the same as char_to_squeeze). */ + for (; i < nr && buf[i] == char_to_squeeze; i++) + continue; + if (i < nr) + char_to_squeeze = NOT_A_CHAR; + /* If (i >= nr) we've squeezed the last character in this buffer. + So now we have to read a new buffer and continue comparing + characters against char_to_squeeze. */ + } + } +} + +static size_t +plain_read (char *buf, size_t size) +{ + size_t nr = safe_read (STDIN_FILENO, buf, size); + if (nr == SAFE_READ_ERROR) + die (EXIT_FAILURE, errno, _("read error")); + return nr; +} + +/* Read buffers of SIZE bytes from stdin until one is found that + contains at least one character not in the delete set. Store + in the array BUF, all characters from that buffer that are not + in the delete set, and return the number of characters saved + or 0 upon EOF. */ + +static size_t +read_and_delete (char *buf, size_t size) +{ + size_t n_saved; + + /* This enclosing do-while loop is to make sure that + we don't return zero (indicating EOF) when we've + just deleted all the characters in a buffer. */ + do + { + size_t nr = plain_read (buf, size); + + if (nr == 0) + return 0; + + /* This first loop may be a waste of code, but gives much + better performance when no characters are deleted in + the beginning of a buffer. It just avoids the copying + of buf[i] into buf[n_saved] when it would be a NOP. */ + + size_t i; + for (i = 0; i < nr && !in_delete_set[to_uchar (buf[i])]; i++) + continue; + n_saved = i; + + for (++i; i < nr; i++) + if (!in_delete_set[to_uchar (buf[i])]) + buf[n_saved++] = buf[i]; + } + while (n_saved == 0); + + return n_saved; +} + +/* Read at most SIZE bytes from stdin into the array BUF. Then + perform the in-place and one-to-one mapping specified by the global + array 'xlate'. Return the number of characters read, or 0 upon EOF. */ + +static size_t +read_and_xlate (char *buf, size_t size) +{ + size_t bytes_read = plain_read (buf, size); + + for (size_t i = 0; i < bytes_read; i++) + buf[i] = xlate[to_uchar (buf[i])]; + + return bytes_read; +} + +/* Initialize a boolean membership set, IN_SET, with the character + values obtained by traversing the linked list of constructs S + using the function 'get_next'. IN_SET is expected to have been + initialized to all zeros by the caller. If COMPLEMENT_THIS_SET + is true the resulting set is complemented. */ + +static void +set_initialize (struct Spec_list *s, bool complement_this_set, bool *in_set) +{ + int c; + + s->state = BEGIN_STATE; + while ((c = get_next (s, NULL)) != -1) + in_set[c] = true; + if (complement_this_set) + for (size_t i = 0; i < N_CHARS; i++) + in_set[i] = (!in_set[i]); +} + +int +main (int argc, char **argv) +{ + int c; + int non_option_args; + int min_operands; + int max_operands; + struct Spec_list buf1, buf2; + struct Spec_list *s1 = &buf1; + struct Spec_list *s2 = &buf2; + + initialize_main (&argc, &argv); + set_program_name (argv[0]); + setlocale (LC_ALL, ""); + bindtextdomain (PACKAGE, LOCALEDIR); + textdomain (PACKAGE); + + atexit (close_stdout); + + while ((c = getopt_long (argc, argv, "+AcCdst", long_options, NULL)) != -1) + { + switch (c) + { + case 'A': + /* Undocumented option, for compatibility with AIX. */ + setlocale (LC_COLLATE, "C"); + setlocale (LC_CTYPE, "C"); + break; + + case 'c': + case 'C': + complement = true; + break; + + case 'd': + delete = true; + break; + + case 's': + squeeze_repeats = true; + break; + + case 't': + truncate_set1 = true; + break; + + case_GETOPT_HELP_CHAR; + + case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS); + + default: + usage (EXIT_FAILURE); + break; + } + } + + non_option_args = argc - optind; + translating = (non_option_args == 2 && !delete); + min_operands = 1 + (delete == squeeze_repeats); + max_operands = 1 + (delete <= squeeze_repeats); + + if (non_option_args < min_operands) + { + if (non_option_args == 0) + error (0, 0, _("missing operand")); + else + { + error (0, 0, _("missing operand after %s"), quote (argv[argc - 1])); + fprintf (stderr, "%s\n", + _(squeeze_repeats + ? N_("Two strings must be given when " + "both deleting and squeezing repeats.") + : N_("Two strings must be given when translating."))); + } + usage (EXIT_FAILURE); + } + + if (max_operands < non_option_args) + { + error (0, 0, _("extra operand %s"), quote (argv[optind + max_operands])); + if (non_option_args == 2) + fprintf (stderr, "%s\n", + _("Only one string may be given when " + "deleting without squeezing repeats.")); + usage (EXIT_FAILURE); + } + + spec_init (s1); + if (!parse_str (argv[optind], s1)) + return EXIT_FAILURE; + + if (non_option_args == 2) + { + spec_init (s2); + if (!parse_str (argv[optind + 1], s2)) + return EXIT_FAILURE; + } + else + s2 = NULL; + + validate (s1, s2); + + /* Use binary I/O, since 'tr' is sometimes used to transliterate + non-printable characters, or characters which are stripped away + by text-mode reads (like CR and ^Z). */ + xset_binary_mode (STDIN_FILENO, O_BINARY); + xset_binary_mode (STDOUT_FILENO, O_BINARY); + fadvise (stdin, FADVISE_SEQUENTIAL); + + if (squeeze_repeats && non_option_args == 1) + { + set_initialize (s1, complement, in_squeeze_set); + squeeze_filter (io_buf, sizeof io_buf, plain_read); + } + else if (delete && non_option_args == 1) + { + set_initialize (s1, complement, in_delete_set); + + while (true) + { + size_t nr = read_and_delete (io_buf, sizeof io_buf); + if (nr == 0) + break; + if (fwrite (io_buf, 1, nr, stdout) != nr) + die (EXIT_FAILURE, errno, _("write error")); + } + } + else if (squeeze_repeats && delete && non_option_args == 2) + { + set_initialize (s1, complement, in_delete_set); + set_initialize (s2, false, in_squeeze_set); + squeeze_filter (io_buf, sizeof io_buf, read_and_delete); + } + else if (translating) + { + if (complement) + { + bool *in_s1 = in_delete_set; + + set_initialize (s1, false, in_s1); + s2->state = BEGIN_STATE; + for (int i = 0; i < N_CHARS; i++) + xlate[i] = i; + for (int i = 0; i < N_CHARS; i++) + { + if (!in_s1[i]) + { + int ch = get_next (s2, NULL); + assert (ch != -1 || truncate_set1); + if (ch == -1) + { + /* This will happen when tr is invoked like e.g. + tr -cs A-Za-z0-9 '\012'. */ + break; + } + xlate[i] = ch; + } + } + } + else + { + int c1, c2; + enum Upper_Lower_class class_s1; + enum Upper_Lower_class class_s2; + + for (int i = 0; i < N_CHARS; i++) + xlate[i] = i; + s1->state = BEGIN_STATE; + s2->state = BEGIN_STATE; + while (true) + { + c1 = get_next (s1, &class_s1); + c2 = get_next (s2, &class_s2); + + if (class_s1 == UL_LOWER && class_s2 == UL_UPPER) + { + for (int i = 0; i < N_CHARS; i++) + if (islower (i)) + xlate[i] = toupper (i); + } + else if (class_s1 == UL_UPPER && class_s2 == UL_LOWER) + { + for (int i = 0; i < N_CHARS; i++) + if (isupper (i)) + xlate[i] = tolower (i); + } + else + { + /* The following should have been checked by validate... */ + if (c1 == -1 || c2 == -1) + break; + xlate[c1] = c2; + } + + /* When case-converting, skip the elements as an optimization. */ + if (class_s2 != UL_NONE) + { + skip_construct (s1); + skip_construct (s2); + } + } + assert (c1 == -1 || truncate_set1); + } + if (squeeze_repeats) + { + set_initialize (s2, false, in_squeeze_set); + squeeze_filter (io_buf, sizeof io_buf, read_and_xlate); + } + else + { + while (true) + { + size_t bytes_read = read_and_xlate (io_buf, sizeof io_buf); + if (bytes_read == 0) + break; + if (fwrite (io_buf, 1, bytes_read, stdout) != bytes_read) + die (EXIT_FAILURE, errno, _("write error")); + } + } + } + + if (close (STDIN_FILENO) != 0) + die (EXIT_FAILURE, errno, _("standard input")); + + return EXIT_SUCCESS; +} |