config/pathsub.c

   1 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5 /*
   6 ** Pathname subroutines.
   7 **
   8 ** Brendan Eich, 8/29/95
   9 */
  10 #include <assert.h>
  11 #include <sys/types.h>
  12 #include <dirent.h>
  13 #include <errno.h>
  14 #include <stdarg.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <unistd.h>
  19 #include <sys/stat.h>
  20 #include "pathsub.h"
  21
  22 #ifdef USE_REENTRANT_LIBC
  23 #  include <libc_r.h>
  24 #endif
  25
  26 #ifdef SUNOS4
  27 #  include "sunos4.h"
  28 #endif
  29
  30 char* program;
  31
  32 void fail(const char* format, ...) {
  33   int error;
  34   va_list ap;
  35
  36 #ifdef USE_REENTRANT_LIBC
  37   R_STRERROR_INIT_R();
  38 #endif
  39
  40   error = errno;
  41   fprintf(stderr, "%s: ", program);
  42   va_start(ap, format);
  43   vfprintf(stderr, format, ap);
  44   va_end(ap);
  45   if (error) {
  46 #ifdef USE_REENTRANT_LIBC
  47     R_STRERROR_R(errno);
  48     fprintf(stderr, ": %s", r_strerror_r);
  49 #else
  50     fprintf(stderr, ": %s", strerror(errno));
  51 #endif
  52   }
  53
  54   putc('\n', stderr);
  55   exit(1);
  56 }
  57
  58 char* getcomponent(char* path, char* name) {
  59   if (*path == '\0') return 0;
  60   if (*path == '/') {
  61     *name++ = '/';
  62   } else {
  63     do {
  64       *name++ = *path++;
  65     } while (*path != '/' && *path != '\0');
  66   }
  67   *name = '\0';
  68   while (*path == '/') path++;
  69   return path;
  70 }
  71
  72 #ifdef LAME_READDIR
  73 #  include <sys/param.h>
  74 /*
  75 ** The static buffer in Unixware's readdir is too small.
  76 */
  77 struct dirent* readdir(DIR* d) {
  78   static struct dirent* buf = NULL;
  79
  80   if (buf == NULL)
  81     buf = (struct dirent*)malloc(sizeof(struct dirent) + MAXPATHLEN);
  82   return (readdir_r(d, buf));
  83 }
  84 #endif
  85
  86 char* ino2name(ino_t ino) {
  87   DIR* dp;
  88   struct dirent* ep;
  89   char* name;
  90
  91   dp = opendir("..");
  92   if (!dp) fail("cannot read parent directory");
  93   for (;;) {
  94     if (!(ep = readdir(dp))) fail("cannot find current directory");
  95     if (ep->d_ino == ino) break;
  96   }
  97   name = xstrdup(ep->d_name);
  98   closedir(dp);
  99   return name;
 100 }
 101
 102 void* xmalloc(size_t size) {
 103   void* p = malloc(size);
 104   if (!p) fail("cannot allocate %u bytes", size);
 105   return p;
 106 }
 107
 108 char* xstrdup(char* s) { return strcpy(xmalloc(strlen(s) + 1), s); }
 109
 110 char* xbasename(char* path) {
 111   char* cp;
 112
 113   while ((cp = strrchr(path, '/')) && cp[1] == '\0') *cp = '\0';
 114   if (!cp) return path;
 115   return cp + 1;
 116 }
 117
 118 void xchdir(const char* dir) {
 119   if (chdir(dir) < 0) fail("cannot change directory to %s", dir);
 120 }
 121
 122 int relatepaths(char* from, char* to, char* outpath) {
 123   char *cp, *cp2;
 124   int len;
 125   char buf[NAME_MAX];
 126
 127   assert(*from == '/' && *to == '/');
 128   for (cp = to, cp2 = from; *cp == *cp2; cp++, cp2++)
 129     if (*cp == '\0') break;
 130   while (cp[-1] != '/') cp--, cp2--;
 131   if (cp - 1 == to) {
 132     /* closest common ancestor is /, so use full pathname */
 133     len = strlen(strcpy(outpath, to));
 134     if (outpath[len] != '/') {
 135       outpath[len++] = '/';
 136       outpath[len] = '\0';
 137     }
 138   } else {
 139     len = 0;
 140     while ((cp2 = getcomponent(cp2, buf)) != 0) {
 141       strcpy(outpath + len, "../");
 142       len += 3;
 143     }
 144     while ((cp = getcomponent(cp, buf)) != 0) {
 145       sprintf(outpath + len, "%s/", buf);
 146       len += strlen(outpath + len);
 147     }
 148   }
 149   return len;
 150 }
 151
 152 void reversepath(char* inpath, char* name, int len, char* outpath) {
 153   char *cp, *cp2;
 154   char buf[NAME_MAX];
 155   struct stat sb;
 156
 157   cp = strcpy(outpath + PATH_MAX - (len + 1), name);
 158   cp2 = inpath;
 159   while ((cp2 = getcomponent(cp2, buf)) != 0) {
 160     if (strcmp(buf, ".") == 0) continue;
 161     if (strcmp(buf, "..") == 0) {
 162       if (stat(".", &sb) < 0) fail("cannot stat current directory");
 163       name = ino2name(sb.st_ino);
 164       len = strlen(name);
 165       cp -= len + 1;
 166       strcpy(cp, name);
 167       cp[len] = '/';
 168       free(name);
 169       xchdir("..");
 170     } else {
 171       cp -= 3;
 172       strncpy(cp, "../", 3);
 173       xchdir(buf);
 174     }
 175   }
 176   strcpy(outpath, cp);
 177 }