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Diffstat (limited to 'examples/loadables/dsv.c')
| -rw-r--r-- | examples/loadables/dsv.c | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/examples/loadables/dsv.c b/examples/loadables/dsv.c new file mode 100644 index 0000000..70e59cb --- /dev/null +++ b/examples/loadables/dsv.c @@ -0,0 +1,300 @@ +/* dsv - process a line of delimiter-separated data and populate an indexed + array with the fields */ + +/* + Copyright (C) 2022 Free Software Foundation, Inc. + + Bash 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. + + Bash 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 Bash. If not, see <http://www.gnu.org/licenses/>. +*/ + +/* See Makefile for compilation details. */ + +#include <config.h> + +#if defined (HAVE_UNISTD_H) +# include <unistd.h> +#endif +#include "bashansi.h" +#include <stdio.h> + +#include "loadables.h" + +#define DSV_ARRAY_DEFAULT "DSV" + +#define NQUOTE 0 +#define DQUOTE 1 +#define SQUOTE 2 + +#define F_SHELLQUOTE 0x01 +#define F_GREEDY 0x02 +#define F_PRESERVE 0x04 + +/* Split LINE into delimiter-separated fields, storing each field into a + separate element of array variable DSV, starting at index 0. The format + of LINE is delimiter-separated values. By default, this splits lines of + CSV data as described in RFC 4180. If *DSTRING is any other value than + ',', this uses that character as a field delimiter. Pass F_SHELLQUOTE in + FLAGS to understand shell-like double-quoting and backslash-escaping in + double quotes instead of the "" CSV behavior, and shell-like single quotes. + Pass F_GREEDY in FLAGS to consume multiple leading and trailing instances + of *DSTRING and consecutive instances of *DSTRING in LINE without creating + null fields. If you want to preserve the quote characters in the generated + fields, pass F_PRESERVE; by default, this removes them. */ +static int +dsvsplit (dsv, line, dstring, flags) + SHELL_VAR *dsv; + char *line, *dstring; + int flags; +{ + arrayind_t ind; + char *field, *prev, *buf, *xbuf; + int delim, qstate; + int b, rval; + + xbuf = 0; + ind = 0; + field = prev = line; + + /* If we want a greedy split, consume leading instances of *DSTRING */ + if (flags & F_GREEDY) + { + while (*prev == *dstring) + prev++; + field = prev; + } + + do + { + if (*prev == '"') + { + if (xbuf == 0) + xbuf = xmalloc (strlen (prev) + 1); + buf = xbuf; + b = 0; + if (flags & F_PRESERVE) + buf[b++] = *prev; + qstate = DQUOTE; + for (field = ++prev; *field; field++) + { + if (qstate == DQUOTE && *field == '"' && field[1] == '"' && (flags & F_SHELLQUOTE) == 0) + buf[b++] = *field++; /* skip double quote */ + else if (qstate == DQUOTE && (flags & F_SHELLQUOTE) && *field == '\\' && strchr (slashify_in_quotes, field[1]) != 0) + buf[b++] = *++field; /* backslash quoted double quote */ + else if (qstate == DQUOTE && *field == '"') + { + qstate = NQUOTE; + if (flags & F_PRESERVE) + buf[b++] = *field; + } + else if (qstate == NQUOTE && *field == *dstring) + break; + else + /* This copies any text between a closing double quote and the + delimiter. If you want to change that, make sure to do the + copy only if qstate == DQUOTE. */ + buf[b++] = *field; + } + buf[b] = '\0'; + } + else if ((flags & F_SHELLQUOTE) && *prev == '\'') + { + if (xbuf == 0) + xbuf = xmalloc (strlen (prev) + 1); + buf = xbuf; + b = 0; + if (flags & F_PRESERVE) + buf[b++] = *prev; + qstate = SQUOTE; + for (field = ++prev; *field; field++) + { + if (qstate == SQUOTE && *field == '\'') + { + qstate = NQUOTE; + if (flags & F_PRESERVE) + buf[b++] = *field; + } + else if (qstate == NQUOTE && *field == *dstring) + break; + else + /* This copies any text between a closing single quote and the + delimiter. If you want to change that, make sure to do the + copy only if qstate == SQUOTE. */ + buf[b++] = *field; + } + buf[b] = '\0'; + } + else + { + buf = prev; + field = prev + strcspn (prev, dstring); + } + + delim = *field; + *field = '\0'; + + if ((flags & F_GREEDY) == 0 || buf[0]) + { + bind_array_element (dsv, ind, buf, 0); + ind++; + } + + *field = delim; + + if (delim == *dstring) + prev = field + 1; + } + while (delim == *dstring); + + if (xbuf) + free (xbuf); + + return (rval = ind); /* number of fields */ +} + +int +dsv_builtin (list) + WORD_LIST *list; +{ + int opt, rval, flags; + char *array_name, *dsvstring, *delims; + SHELL_VAR *v; + + array_name = 0; + rval = EXECUTION_SUCCESS; + + delims = ","; + flags = 0; + + reset_internal_getopt (); + while ((opt = internal_getopt (list, "a:d:Sgp")) != -1) + { + switch (opt) + { + case 'a': + array_name = list_optarg; + break; + case 'd': + delims = list_optarg; + break; + case 'S': + flags |= F_SHELLQUOTE; + break; + case 'g': + flags |= F_GREEDY; + break; + case 'p': + flags |= F_PRESERVE; + break; + CASE_HELPOPT; + default: + builtin_usage (); + return (EX_USAGE); + } + } + list = loptend; + + if (array_name == 0) + array_name = DSV_ARRAY_DEFAULT; + + if (legal_identifier (array_name) == 0) + { + sh_invalidid (array_name); + return (EXECUTION_FAILURE); + } + + if (list == 0) + { + builtin_error ("dsv string argument required"); + return (EX_USAGE); + } + + v = find_or_make_array_variable (array_name, 1); + if (v == 0 || readonly_p (v) || noassign_p (v)) + { + if (v && readonly_p (v)) + err_readonly (array_name); + return (EXECUTION_FAILURE); + } + else if (array_p (v) == 0) + { + builtin_error ("%s: not an indexed array", array_name); + return (EXECUTION_FAILURE); + } + if (invisible_p (v)) + VUNSETATTR (v, att_invisible); + array_flush (array_cell (v)); + + dsvstring = list->word->word; + + if (dsvstring == 0 || *dsvstring == 0) + return (EXECUTION_SUCCESS); + + opt = dsvsplit (v, dsvstring, delims, flags); + /* Maybe do something with OPT here, it's the number of fields */ + + return (rval); +} + +/* Called when builtin is enabled and loaded from the shared object. If this + function returns 0, the load fails. */ +int +dsv_builtin_load (name) + char *name; +{ + return (1); +} + +/* Called when builtin is disabled. */ +void +dsv_builtin_unload (name) + char *name; +{ +} + +char *dsv_doc[] = { + "Read delimiter-separated fields from STRING.", + "", + "Parse STRING, a line of delimiter-separated values, into individual", + "fields, and store them into the indexed array ARRAYNAME starting at", + "index 0. The parsing understands and skips over double-quoted strings. ", + "If ARRAYNAME is not supplied, \"DSV\" is the default array name.", + "If the delimiter is a comma, the default, this parses comma-", + "separated values as specified in RFC 4180.", + "", + "The -d option specifies the delimiter. The delimiter is the first", + "character of the DELIMS argument. Specifying a DELIMS argument that", + "contains more than one character is not supported and will produce", + "unexpected results. The -S option enables shell-like quoting: double-", + "quoted strings can contain backslashes preceding special characters,", + "and the backslash will be removed; and single-quoted strings are", + "processed as the shell would process them. The -g option enables a", + "greedy split: sequences of the delimiter are skipped at the beginning", + "and end of STRING, and consecutive instances of the delimiter in STRING", + "do not generate empty fields. If the -p option is supplied, dsv leaves", + "quote characters as part of the generated field; otherwise they are", + "removed.", + "", + "The return value is 0 unless an invalid option is supplied or the ARRAYNAME", + "argument is invalid or readonly.", + (char *)NULL +}; + +struct builtin dsv_struct = { + "dsv", /* builtin name */ + dsv_builtin, /* function implementing the builtin */ + BUILTIN_ENABLED, /* initial flags for builtin */ + dsv_doc, /* array of long documentation strings. */ + "dsv [-a ARRAYNAME] [-d DELIMS] [-Sgp] string", /* usage synopsis; becomes short_doc */ + 0 /* reserved for internal use */ +}; |