[8833] | 1 | /* getpwd.c - get the working directory */ |
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| 2 | |
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| 3 | #include "config.h" |
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| 4 | |
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| 5 | #include <errno.h> |
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| 6 | #include <sys/types.h> |
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| 7 | #include <sys/stat.h> |
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| 8 | |
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| 9 | #ifndef errno |
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| 10 | extern int errno; |
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| 11 | #endif |
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| 12 | |
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| 13 | /* Virtually every UN*X system now in common use (except for pre-4.3-tahoe |
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| 14 | BSD systems) now provides getcwd as called for by POSIX. Allow for |
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| 15 | the few exceptions to the general rule here. */ |
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| 16 | |
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| 17 | #if !(defined (POSIX) || defined (USG) || defined (VMS)) || defined (HAVE_GETWD) |
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| 18 | #include <sys/param.h> |
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| 19 | extern char *getwd (); |
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| 20 | #define getcwd(buf,len) getwd(buf) |
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| 21 | #ifdef MAXPATHLEN |
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| 22 | #define GUESSPATHLEN (MAXPATHLEN + 1) |
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| 23 | #else |
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| 24 | #define GUESSPATHLEN 100 |
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| 25 | #endif |
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| 26 | #else /* (defined (USG) || defined (VMS)) */ |
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| 27 | extern char *getcwd (); |
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| 28 | /* We actually use this as a starting point, not a limit. */ |
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| 29 | #define GUESSPATHLEN 100 |
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| 30 | #endif /* (defined (USG) || defined (VMS)) */ |
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| 31 | #ifdef _WIN32 |
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| 32 | #include <direct.h> |
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| 33 | #endif |
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| 34 | |
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| 35 | char *getenv (); |
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| 36 | char *xmalloc (); |
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| 37 | |
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| 38 | #ifndef VMS |
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| 39 | |
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| 40 | /* Get the working directory. Use the PWD environment variable if it's |
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| 41 | set correctly, since this is faster and gives more uniform answers |
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| 42 | to the user. Yield the working directory if successful; otherwise, |
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| 43 | yield 0 and set errno. */ |
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| 44 | |
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| 45 | char * |
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| 46 | getpwd () |
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| 47 | { |
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| 48 | static char *pwd; |
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| 49 | static int failure_errno; |
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| 50 | |
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| 51 | char *p = pwd; |
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| 52 | size_t s; |
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| 53 | struct stat dotstat, pwdstat; |
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| 54 | |
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| 55 | if (!p && !(errno = failure_errno)) |
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| 56 | { |
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| 57 | if (! ((p = getenv ("PWD")) != 0 |
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| 58 | && *p == '/' |
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| 59 | && stat (p, &pwdstat) == 0 |
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| 60 | && stat (".", &dotstat) == 0 |
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| 61 | && dotstat.st_ino == pwdstat.st_ino |
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| 62 | && dotstat.st_dev == pwdstat.st_dev)) |
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| 63 | |
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| 64 | /* The shortcut didn't work. Try the slow, ``sure'' way. */ |
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| 65 | for (s = GUESSPATHLEN; ! getcwd (p = xmalloc (s), s); s *= 2) |
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| 66 | { |
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| 67 | int e = errno; |
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| 68 | free (p); |
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| 69 | #ifdef ERANGE |
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| 70 | if (e != ERANGE) |
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| 71 | #endif |
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| 72 | { |
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| 73 | errno = failure_errno = e; |
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| 74 | p = 0; |
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| 75 | break; |
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| 76 | } |
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| 77 | } |
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| 78 | |
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| 79 | /* Cache the result. This assumes that the program does |
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| 80 | not invoke chdir between calls to getpwd. */ |
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| 81 | pwd = p; |
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| 82 | } |
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| 83 | return p; |
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| 84 | } |
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| 85 | |
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| 86 | #else /* VMS */ |
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| 87 | |
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| 88 | #ifndef MAXPATHLEN |
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| 89 | #define MAXPATHLEN 255 |
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| 90 | #endif |
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| 91 | |
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| 92 | char * |
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| 93 | getpwd () |
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| 94 | { |
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| 95 | static char *pwd = 0; |
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| 96 | |
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| 97 | if (!pwd) pwd = getcwd (xmalloc (MAXPATHLEN+1), MAXPATHLEN+1); |
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| 98 | return pwd; |
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| 99 | } |
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| 100 | |
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| 101 | #endif /* VMS */ |
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