diff options
Diffstat (limited to 'src/expand-common.c')
| -rw-r--r-- | src/expand-common.c | 400 |
1 files changed, 400 insertions, 0 deletions
diff --git a/src/expand-common.c b/src/expand-common.c new file mode 100644 index 0000000..e4209a0 --- /dev/null +++ b/src/expand-common.c @@ -0,0 +1,400 @@ +/* expand-common - common functionality for expand/unexapnd + Copyright (C) 1989-2020 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/>. */ + +#include <config.h> + +#include <assert.h> +#include <stdio.h> +#include <sys/types.h> +#include "system.h" +#include "die.h" +#include "error.h" +#include "fadvise.h" +#include "quote.h" +#include "xstrndup.h" + +#include "expand-common.h" + +/* If true, convert blanks even after nonblank characters have been + read on the line. */ +bool convert_entire_line = false; + +/* If nonzero, the size of all tab stops. If zero, use 'tab_list' instead. */ +static uintmax_t tab_size = 0; + +/* If nonzero, the size of all tab stops after the last specifed. */ +static uintmax_t extend_size = 0; + +/* If nonzero, an increment for additional tab stops after the last specified.*/ +static uintmax_t increment_size = 0; + +/* The maximum distance between tab stops. */ +size_t max_column_width; + +/* Array of the explicit column numbers of the tab stops; + after 'tab_list' is exhausted, each additional tab is replaced + by a space. The first column is column 0. */ +static uintmax_t *tab_list = NULL; + +/* The number of allocated entries in 'tab_list'. */ +static size_t n_tabs_allocated = 0; + +/* The index of the first invalid element of 'tab_list', + where the next element can be added. */ +static size_t first_free_tab = 0; + +/* Null-terminated array of input filenames. */ +static char **file_list = NULL; + +/* Default for 'file_list' if no files are given on the command line. */ +static char *stdin_argv[] = +{ + (char *) "-", NULL +}; + +/* True if we have ever read standard input. */ +static bool have_read_stdin = false; + +/* The desired exit status. */ +int exit_status = EXIT_SUCCESS; + + + +/* Add tab stop TABVAL to the end of 'tab_list'. */ +extern void +add_tab_stop (uintmax_t tabval) +{ + uintmax_t prev_column = first_free_tab ? tab_list[first_free_tab - 1] : 0; + uintmax_t column_width = prev_column <= tabval ? tabval - prev_column : 0; + + if (first_free_tab == n_tabs_allocated) + tab_list = X2NREALLOC (tab_list, &n_tabs_allocated); + tab_list[first_free_tab++] = tabval; + + if (max_column_width < column_width) + { + if (SIZE_MAX < column_width) + die (EXIT_FAILURE, 0, _("tabs are too far apart")); + max_column_width = column_width; + } +} + +static bool +set_extend_size (uintmax_t tabval) +{ + bool ok = true; + + if (extend_size) + { + error (0, 0, + _("'/' specifier only allowed" + " with the last value")); + ok = false; + } + extend_size = tabval; + + return ok; +} + +static bool +set_increment_size (uintmax_t tabval) +{ + bool ok = true; + + if (increment_size) + { + error (0,0, + _("'+' specifier only allowed" + " with the last value")); + ok = false; + } + increment_size = tabval; + + return ok; +} + +/* Add the comma or blank separated list of tab stops STOPS + to the list of tab stops. */ +extern void +parse_tab_stops (char const *stops) +{ + bool have_tabval = false; + uintmax_t tabval = 0; + bool extend_tabval = false; + bool increment_tabval = false; + char const *num_start = NULL; + bool ok = true; + + for (; *stops; stops++) + { + if (*stops == ',' || isblank (to_uchar (*stops))) + { + if (have_tabval) + { + if (extend_tabval) + { + if (! set_extend_size (tabval)) + { + ok = false; + break; + } + } + else if (increment_tabval) + { + if (! set_increment_size (tabval)) + { + ok = false; + break; + } + } + else + add_tab_stop (tabval); + } + have_tabval = false; + } + else if (*stops == '/') + { + if (have_tabval) + { + error (0, 0, _("'/' specifier not at start of number: %s"), + quote (stops)); + ok = false; + } + extend_tabval = true; + increment_tabval = false; + } + else if (*stops == '+') + { + if (have_tabval) + { + error (0, 0, _("'+' specifier not at start of number: %s"), + quote (stops)); + ok = false; + } + increment_tabval = true; + extend_tabval = false; + } + else if (ISDIGIT (*stops)) + { + if (!have_tabval) + { + tabval = 0; + have_tabval = true; + num_start = stops; + } + + /* Detect overflow. */ + if (!DECIMAL_DIGIT_ACCUMULATE (tabval, *stops - '0', uintmax_t)) + { + size_t len = strspn (num_start, "0123456789"); + char *bad_num = xstrndup (num_start, len); + error (0, 0, _("tab stop is too large %s"), quote (bad_num)); + free (bad_num); + ok = false; + stops = num_start + len - 1; + } + } + else + { + error (0, 0, _("tab size contains invalid character(s): %s"), + quote (stops)); + ok = false; + break; + } + } + + if (ok && have_tabval) + { + if (extend_tabval) + ok &= set_extend_size (tabval); + else if (increment_tabval) + ok &= set_increment_size (tabval); + else + add_tab_stop (tabval); + } + + if (! ok) + exit (EXIT_FAILURE); +} + +/* Check that the list of tab stops TABS, with ENTRIES entries, + contains only nonzero, ascending values. */ + +static void +validate_tab_stops (uintmax_t const *tabs, size_t entries) +{ + uintmax_t prev_tab = 0; + + for (size_t i = 0; i < entries; i++) + { + if (tabs[i] == 0) + die (EXIT_FAILURE, 0, _("tab size cannot be 0")); + if (tabs[i] <= prev_tab) + die (EXIT_FAILURE, 0, _("tab sizes must be ascending")); + prev_tab = tabs[i]; + } + + if (increment_size && extend_size) + die (EXIT_FAILURE, 0, _("'/' specifier is mutually exclusive with '+'")); +} + +/* Called after all command-line options have been parsed, + and add_tab_stop/parse_tab_stops have been called. + Will validate the tab-stop values, + and set the final values to: + tab-stops = 8 (if no tab-stops given on command line) + tab-stops = N (if value N specified as the only value). + tab-stops = distinct values given on command line (if multiple values given). +*/ +extern void +finalize_tab_stops (void) +{ + validate_tab_stops (tab_list, first_free_tab); + + if (first_free_tab == 0) + tab_size = max_column_width = extend_size + ? extend_size : increment_size + ? increment_size : 8; + else if (first_free_tab == 1 && ! extend_size && ! increment_size) + tab_size = tab_list[0]; + else + tab_size = 0; +} + + +extern uintmax_t +get_next_tab_column (const uintmax_t column, size_t* tab_index, + bool* last_tab) +{ + *last_tab = false; + + /* single tab-size - return multiples of it */ + if (tab_size) + return column + (tab_size - column % tab_size); + + /* multiple tab-sizes - iterate them until the tab position is beyond + the current input column. */ + for ( ; *tab_index < first_free_tab ; (*tab_index)++ ) + { + uintmax_t tab = tab_list[*tab_index]; + if (column < tab) + return tab; + } + + /* relative last tab - return multiples of it */ + if (extend_size) + return column + (extend_size - column % extend_size); + + /* incremental last tab - add increment_size to the previous tab stop */ + if (increment_size) + { + uintmax_t end_tab = tab_list[first_free_tab - 1]; + + return column + (increment_size - ((column - end_tab) % increment_size)); + } + + *last_tab = true; + return 0; +} + + + + +/* Sets new file-list */ +extern void +set_file_list (char **list) +{ + have_read_stdin = false; + + if (!list) + file_list = stdin_argv; + else + file_list = list; +} + +/* Close the old stream pointer FP if it is non-NULL, + and return a new one opened to read the next input file. + Open a filename of '-' as the standard input. + Return NULL if there are no more input files. */ + +extern FILE * +next_file (FILE *fp) +{ + static char *prev_file; + char *file; + + if (fp) + { + assert (prev_file); + if (ferror (fp)) + { + error (0, errno, "%s", quotef (prev_file)); + exit_status = EXIT_FAILURE; + } + if (STREQ (prev_file, "-")) + clearerr (fp); /* Also clear EOF. */ + else if (fclose (fp) != 0) + { + error (0, errno, "%s", quotef (prev_file)); + exit_status = EXIT_FAILURE; + } + } + + while ((file = *file_list++) != NULL) + { + if (STREQ (file, "-")) + { + have_read_stdin = true; + fp = stdin; + } + else + fp = fopen (file, "r"); + if (fp) + { + prev_file = file; + fadvise (fp, FADVISE_SEQUENTIAL); + return fp; + } + error (0, errno, "%s", quotef (file)); + exit_status = EXIT_FAILURE; + } + return NULL; +} + +/* */ +extern void +cleanup_file_list_stdin (void) +{ + if (have_read_stdin && fclose (stdin) != 0) + die (EXIT_FAILURE, errno, "-"); +} + + +extern void +emit_tab_list_info (void) +{ + /* suppress syntax check for emit_mandatory_arg_note() */ + fputs (_("\ + -t, --tabs=LIST use comma separated list of tab positions\n\ +"), stdout); + fputs (_("\ + The last specified position can be prefixed with '/'\n\ + to specify a tab size to use after the last\n\ + explicitly specified tab stop. Also a prefix of '+'\n\ + can be used to align remaining tab stops relative to\n\ + the last specified tab stop instead of the first column\n\ +"), stdout); +} |