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Diffstat (limited to 'lib/sh/spell.c')
| -rw-r--r-- | lib/sh/spell.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/lib/sh/spell.c b/lib/sh/spell.c new file mode 100644 index 0000000..d0394c2 --- /dev/null +++ b/lib/sh/spell.c @@ -0,0 +1,212 @@ +/* spell.c -- spelling correction for pathnames. */ + +/* Copyright (C) 2000 Free Software Foundation, Inc. + + This file is part of GNU Bash, the Bourne Again SHell. + + 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/>. +*/ + +#include <config.h> + +#if defined (HAVE_UNISTD_H) +# ifdef _MINIX +# include <sys/types.h> +# endif +# include <unistd.h> +#endif + +#include <bashtypes.h> +#include <posixdir.h> +#include <posixstat.h> +#ifndef _MINIX +#include <sys/param.h> +#endif + +#include <stdio.h> + +#include <bashansi.h> +#include <maxpath.h> +#include <stdc.h> + +static int mindist __P((char *, char *, char *)); +static int spdist __P((char *, char *)); + +/* + * `spname' and its helpers are inspired by the code in "The UNIX + * Programming Environment", Kernighan & Pike, Prentice-Hall 1984, + * pages 209 - 213. + */ + +/* + * `spname' -- return a correctly spelled filename + * + * int spname(char * oldname, char * newname) + * Returns: -1 if no reasonable match found + * 0 if exact match found + * 1 if corrected + * Stores corrected name in `newname'. + */ +int +spname(oldname, newname) + char *oldname; + char *newname; +{ + char *op, *np, *p; + char guess[PATH_MAX + 1], best[PATH_MAX + 1]; + + op = oldname; + np = newname; + for (;;) + { + while (*op == '/') /* Skip slashes */ + *np++ = *op++; + *np = '\0'; + + if (*op == '\0') /* Exact or corrected */ + { + /* `.' is rarely the right thing. */ + if (oldname[1] == '\0' && newname[1] == '\0' && + oldname[0] != '.' && newname[0] == '.') + return -1; + return strcmp(oldname, newname) != 0; + } + + /* Copy next component into guess */ + for (p = guess; *op != '/' && *op != '\0'; op++) + if (p < guess + PATH_MAX) + *p++ = *op; + *p = '\0'; + + if (mindist(newname, guess, best) >= 3) + return -1; /* Hopeless */ + + /* + * Add to end of newname + */ + for (p = best; *np = *p++; np++) + ; + } +} + +/* + * Search directory for a guess + */ +static int +mindist(dir, guess, best) + char *dir; + char *guess; + char *best; +{ + DIR *fd; + struct dirent *dp; + int dist, x; + + dist = 3; /* Worst distance */ + if (*dir == '\0') + dir = "."; + + if ((fd = opendir(dir)) == NULL) + return dist; + + while ((dp = readdir(fd)) != NULL) + { + /* + * Look for a better guess. If the new guess is as + * good as the current one, we take it. This way, + * any single character match will be a better match + * than ".". + */ + x = spdist(dp->d_name, guess); + if (x <= dist && x != 3) + { + strcpy(best, dp->d_name); + dist = x; + if (dist == 0) /* Exact match */ + break; + } + } + (void)closedir(fd); + + /* Don't return `.' */ + if (best[0] == '.' && best[1] == '\0') + dist = 3; + return dist; +} + +/* + * `spdist' -- return the "distance" between two names. + * + * int spname(char * oldname, char * newname) + * Returns: 0 if strings are identical + * 1 if two characters are transposed + * 2 if one character is wrong, added or deleted + * 3 otherwise + */ +static int +spdist(cur, new) + char *cur, *new; +{ + while (*cur == *new) + { + if (*cur == '\0') + return 0; /* Exact match */ + cur++; + new++; + } + + if (*cur) + { + if (*new) + { + if (cur[1] && new[1] && cur[0] == new[1] && cur[1] == new[0] && strcmp (cur + 2, new + 2) == 0) + return 1; /* Transposition */ + + if (strcmp (cur + 1, new + 1) == 0) + return 2; /* One character mismatch */ + } + + if (strcmp(&cur[1], &new[0]) == 0) + return 2; /* Extra character */ + } + + if (*new && strcmp(cur, new + 1) == 0) + return 2; /* Missing character */ + + return 3; +} + +char * +dirspell (dirname) + char *dirname; +{ + int n; + char *guess; + + n = (strlen (dirname) * 3 + 1) / 2 + 1; + guess = (char *)malloc (n); + if (guess == 0) + return 0; + + switch (spname (dirname, guess)) + { + case -1: + default: + free (guess); + return (char *)NULL; + case 0: + case 1: + return guess; + } +} |