diff options
Diffstat (limited to 'Src/compat.c')
| -rw-r--r-- | Src/compat.c | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/Src/compat.c b/Src/compat.c index 38f24d7fe..ec3a8bc39 100644 --- a/Src/compat.c +++ b/Src/compat.c @@ -227,6 +227,26 @@ zopenmax(void) } #endif +/* + * Rationalise the current directory, returning the string. + * + * If "d" is not NULL, it is used to store information about the + * directory. The returned name is also present in d->dirname and is in + * permanently allocated memory. The handling of this case depends on + * whether the fchdir() system call is available; if it is, it is assumed + * the caller is able to restore the current directory. On successfully + * identifying the directory the function returns immediately rather + * than ascending the hierarchy. + * + * If "d" is NULL, no assumption about the caller's behaviour is + * made. The returned string is in heap memory. This case is + * always handled by changing directory up the hierarchy. + * + * On Cygwin or other systems where USE_GETCWD is defined (at the + * time of writing only QNX), we skip all the above and use the + * getcwd() system call. + */ + /**/ mod_export char * zgetdir(struct dirsav *d) @@ -257,25 +277,30 @@ zgetdir(struct dirsav *d) return buf; } + /* Record the initial inode and device */ pino = sbuf.st_ino; pdev = sbuf.st_dev; if (d) d->ino = pino, d->dev = pdev; +#if !defined(__CYGWIN__) && !defined(USE_GETCWD) #ifdef HAVE_FCHDIR else #endif -#if !defined(__CYGWIN__) && !defined(USE_GETCWD) holdintr(); for (;;) { + /* Examine the parent of the current directory. */ if (stat("..", &sbuf) < 0) break; + /* Inode and device of curtent directory */ ino = pino; dev = pdev; + /* Inode and device of current directory's parent */ pino = sbuf.st_ino; pdev = sbuf.st_dev; + /* If they're the same, we've reached the root directory. */ if (ino == pino && dev == pdev) { if (!buf[pos]) buf[--pos] = '/'; @@ -291,6 +316,7 @@ zgetdir(struct dirsav *d) return buf + pos; } + /* Search the parent for the current directory. */ if (!(dir = opendir(".."))) break; @@ -303,6 +329,7 @@ zgetdir(struct dirsav *d) continue; #ifdef HAVE_STRUCT_DIRENT_D_STAT if(de->d_stat.st_dev == dev && de->d_stat.st_ino == ino) { + /* Found the directory we're currently in */ strncpy(nbuf + 3, fn, PATH_MAX); break; } @@ -311,6 +338,7 @@ zgetdir(struct dirsav *d) if (dev != pdev || (ino_t) de->d_ino == ino) # endif /* HAVE_STRUCT_DIRENT_D_INO */ { + /* Maybe found directory, need to check device & inode */ strncpy(nbuf + 3, fn, PATH_MAX); lstat(nbuf, &sbuf); if (sbuf.st_dev == dev && sbuf.st_ino == ino) @@ -320,7 +348,7 @@ zgetdir(struct dirsav *d) } closedir(dir); if (!de) - break; + break; /* Not found */ len = strlen(nbuf + 2); pos -= len; while (pos <= 1) { |