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Diffstat (limited to 'lib/argmatch.c')
-rw-r--r-- | lib/argmatch.c | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/lib/argmatch.c b/lib/argmatch.c new file mode 100644 index 0000000..2a28900 --- /dev/null +++ b/lib/argmatch.c @@ -0,0 +1,295 @@ +/* argmatch.c -- find a match for a string in an array + + Copyright (C) 1990, 1998-1999, 2001-2007, 2009-2022 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 David MacKenzie <djm@ai.mit.edu> + Modified by Akim Demaille <demaille@inf.enst.fr> */ + +#include <config.h> + +/* Specification. */ +#include "argmatch.h" + +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#define _(msgid) gettext (msgid) + +#include "error.h" +#include "quotearg.h" +#include "getprogname.h" + +#if USE_UNLOCKED_IO +# include "unlocked-io.h" +#endif + +/* When reporting an invalid argument, show nonprinting characters + by using the quoting style ARGMATCH_QUOTING_STYLE. Do not use + literal_quoting_style. */ +#ifndef ARGMATCH_QUOTING_STYLE +# define ARGMATCH_QUOTING_STYLE locale_quoting_style +#endif + +/* Non failing version of argmatch call this function after failing. */ +#ifndef ARGMATCH_DIE +# include "exitfail.h" +# define ARGMATCH_DIE exit (exit_failure) +#endif + +#ifdef ARGMATCH_DIE_DECL +ARGMATCH_DIE_DECL; +#endif + +static void +__argmatch_die (void) +{ + ARGMATCH_DIE; +} + +/* Used by XARGMATCH. See description in argmatch.h. + Default to __argmatch_die, but allow caller to change this at run-time. */ +argmatch_exit_fn argmatch_die = __argmatch_die; + + +/* If ARG is an unambiguous match for an element of the + NULL-terminated array ARGLIST, return the index in ARGLIST + of the matched element, else -1 if it does not match any element + or -2 if it is ambiguous (is a prefix of more than one element). + + If VALLIST is none null, use it to resolve ambiguities limited to + synonyms, i.e., for + "yes", "yop" -> 0 + "no", "nope" -> 1 + "y" is a valid argument, for 0, and "n" for 1. */ + +ptrdiff_t +argmatch (const char *arg, const char *const *arglist, + const void *vallist, size_t valsize) +{ + size_t i; /* Temporary index in ARGLIST. */ + size_t arglen; /* Length of ARG. */ + ptrdiff_t matchind = -1; /* Index of first nonexact match. */ + bool ambiguous = false; /* If true, multiple nonexact match(es). */ + + arglen = strlen (arg); + + /* Test all elements for either exact match or abbreviated matches. */ + for (i = 0; arglist[i]; i++) + { + if (!strncmp (arglist[i], arg, arglen)) + { + if (strlen (arglist[i]) == arglen) + /* Exact match found. */ + return i; + else if (matchind == -1) + /* First nonexact match found. */ + matchind = i; + else + { + /* Second nonexact match found. */ + if (vallist == NULL + || memcmp ((char const *) vallist + valsize * matchind, + (char const *) vallist + valsize * i, valsize)) + { + /* There is a real ambiguity, or we could not + disambiguate. */ + ambiguous = true; + } + } + } + } + if (ambiguous) + return -2; + else + return matchind; +} + +ptrdiff_t +argmatch_exact (const char *arg, const char *const *arglist) +{ + size_t i; + + /* Test elements for exact match. */ + for (i = 0; arglist[i]; i++) + { + if (!strcmp (arglist[i], arg)) + return i; + } + + return -1; +} + +/* Error reporting for argmatch. + CONTEXT is a description of the type of entity that was being matched. + VALUE is the invalid value that was given. + PROBLEM is the return value from argmatch. */ + +void +argmatch_invalid (const char *context, const char *value, ptrdiff_t problem) +{ + char const *format = (problem == -1 + ? _("invalid argument %s for %s") + : _("ambiguous argument %s for %s")); + + error (0, 0, format, quotearg_n_style (0, ARGMATCH_QUOTING_STYLE, value), + quote_n (1, context)); +} + +/* List the valid arguments for argmatch. + ARGLIST is the same as in argmatch. + VALLIST is a pointer to an array of values. + VALSIZE is the size of the elements of VALLIST */ +void +argmatch_valid (const char *const *arglist, + const void *vallist, size_t valsize) +{ + size_t i; + const char *last_val = NULL; + + /* We try to put synonyms on the same line. The assumption is that + synonyms follow each other */ + fputs (_("Valid arguments are:"), stderr); + for (i = 0; arglist[i]; i++) + if ((i == 0) + || memcmp (last_val, (char const *) vallist + valsize * i, valsize)) + { + fprintf (stderr, "\n - %s", quote (arglist[i])); + last_val = (char const *) vallist + valsize * i; + } + else + { + fprintf (stderr, ", %s", quote (arglist[i])); + } + putc ('\n', stderr); +} + +/* Never failing versions of the previous functions. + + CONTEXT is the context for which argmatch is called (e.g., + "--version-control", or "$VERSION_CONTROL" etc.). Upon failure, + calls the (supposed never to return) function EXIT_FN. */ + +ptrdiff_t +__xargmatch_internal (const char *context, + const char *arg, const char *const *arglist, + const void *vallist, size_t valsize, + argmatch_exit_fn exit_fn, + bool allow_abbreviation) +{ + ptrdiff_t res; + + if (allow_abbreviation) + res = argmatch (arg, arglist, vallist, valsize); + else + res = argmatch_exact (arg, arglist); + + if (res >= 0) + /* Success. */ + return res; + + /* We failed. Explain why. */ + argmatch_invalid (context, arg, res); + argmatch_valid (arglist, vallist, valsize); + (*exit_fn) (); + + return -1; /* To please the compilers. */ +} + +/* Look for VALUE in VALLIST, an array of objects of size VALSIZE and + return the first corresponding argument in ARGLIST */ +const char * +argmatch_to_argument (const void *value, + const char *const *arglist, + const void *vallist, size_t valsize) +{ + size_t i; + + for (i = 0; arglist[i]; i++) + if (!memcmp (value, (char const *) vallist + valsize * i, valsize)) + return arglist[i]; + return NULL; +} + +#ifdef TEST +/* + * Based on "getversion.c" by David MacKenzie <djm@gnu.ai.mit.edu> + */ + +/* When to make backup files. */ +enum backup_type +{ + /* Never make backups. */ + no_backups, + + /* Make simple backups of every file. */ + simple_backups, + + /* Make numbered backups of files that already have numbered backups, + and simple backups of the others. */ + numbered_existing_backups, + + /* Make numbered backups of every file. */ + numbered_backups +}; + +/* Two tables describing arguments (keys) and their corresponding + values */ +static const char *const backup_args[] = +{ + "no", "none", "off", + "simple", "never", + "existing", "nil", + "numbered", "t", + 0 +}; + +static const enum backup_type backup_vals[] = +{ + no_backups, no_backups, no_backups, + simple_backups, simple_backups, + numbered_existing_backups, numbered_existing_backups, + numbered_backups, numbered_backups +}; + +int +main (int argc, const char *const *argv) +{ + const char *cp; + enum backup_type backup_type = no_backups; + + if (argc > 2) + { + fprintf (stderr, "Usage: %s [VERSION_CONTROL]\n", getprogname ()); + exit (1); + } + + if ((cp = getenv ("VERSION_CONTROL"))) + backup_type = XARGMATCH ("$VERSION_CONTROL", cp, + backup_args, backup_vals); + + if (argc == 2) + backup_type = XARGMATCH (getprogname (), argv[1], + backup_args, backup_vals); + + printf ("The version control is '%s'\n", + ARGMATCH_TO_ARGUMENT (&backup_type, backup_args, backup_vals)); + + return 0; +} +#endif |