/* 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 2, 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; see the file COPYING. If not, write to the Free Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */ #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; }