| 1 | /* getpwd.c - get the working directory */ |
| 2 | |
| 3 | /* |
| 4 | |
| 5 | @deftypefn Supplemental char* getpwd (void) |
| 6 | |
| 7 | Returns the current working directory. This implementation caches the |
| 8 | result on the assumption that the process will not call @code{chdir} |
| 9 | between calls to @code{getpwd}. |
| 10 | |
| 11 | @end deftypefn |
| 12 | |
| 13 | */ |
| 14 | |
| 15 | #ifdef HAVE_CONFIG_H |
| 16 | #include "config.h" |
| 17 | #endif |
| 18 | |
| 19 | #include <sys/types.h> |
| 20 | |
| 21 | #include <errno.h> |
| 22 | #ifndef errno |
| 23 | extern int errno; |
| 24 | #endif |
| 25 | |
| 26 | #ifdef HAVE_STDLIB_H |
| 27 | #include <stdlib.h> |
| 28 | #endif |
| 29 | #ifdef HAVE_UNISTD_H |
| 30 | #include <unistd.h> |
| 31 | #endif |
| 32 | #ifdef HAVE_SYS_PARAM_H |
| 33 | #include <sys/param.h> |
| 34 | #endif |
| 35 | #if HAVE_SYS_STAT_H |
| 36 | #include <sys/stat.h> |
| 37 | #endif |
| 38 | #if HAVE_LIMITS_H |
| 39 | #include <limits.h> |
| 40 | #endif |
| 41 | |
| 42 | #include "libiberty.h" |
| 43 | |
| 44 | /* Virtually every UN*X system now in common use (except for pre-4.3-tahoe |
| 45 | BSD systems) now provides getcwd as called for by POSIX. Allow for |
| 46 | the few exceptions to the general rule here. */ |
| 47 | |
| 48 | #if !defined(HAVE_GETCWD) && defined(HAVE_GETWD) |
| 49 | /* Prototype in case the system headers doesn't provide it. */ |
| 50 | extern char *getwd (); |
| 51 | #define getcwd(buf,len) getwd(buf) |
| 52 | #endif |
| 53 | |
| 54 | #ifdef MAXPATHLEN |
| 55 | #define GUESSPATHLEN (MAXPATHLEN + 1) |
| 56 | #else |
| 57 | #define GUESSPATHLEN 100 |
| 58 | #endif |
| 59 | |
| 60 | #if !(defined (VMS) || (defined(_WIN32) && !defined(__CYGWIN__))) |
| 61 | |
| 62 | /* Get the working directory. Use the PWD environment variable if it's |
| 63 | set correctly, since this is faster and gives more uniform answers |
| 64 | to the user. Yield the working directory if successful; otherwise, |
| 65 | yield 0 and set errno. */ |
| 66 | |
| 67 | char * |
| 68 | getpwd (void) |
| 69 | { |
| 70 | static char *pwd; |
| 71 | static int failure_errno; |
| 72 | |
| 73 | char *p = pwd; |
| 74 | size_t s; |
| 75 | struct stat dotstat, pwdstat; |
| 76 | |
| 77 | if (!p && !(errno = failure_errno)) |
| 78 | { |
| 79 | if (! ((p = getenv ("PWD")) != 0 |
| 80 | && *p == '/' |
| 81 | && stat (p, &pwdstat) == 0 |
| 82 | && stat (".", &dotstat) == 0 |
| 83 | && dotstat.st_ino == pwdstat.st_ino |
| 84 | && dotstat.st_dev == pwdstat.st_dev)) |
| 85 | |
| 86 | /* The shortcut didn't work. Try the slow, ``sure'' way. */ |
| 87 | for (s = GUESSPATHLEN; !getcwd (p = XNEWVEC (char, s), s); s *= 2) |
| 88 | { |
| 89 | int e = errno; |
| 90 | free (p); |
| 91 | #ifdef ERANGE |
| 92 | if (e != ERANGE) |
| 93 | #endif |
| 94 | { |
| 95 | errno = failure_errno = e; |
| 96 | p = 0; |
| 97 | break; |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | /* Cache the result. This assumes that the program does |
| 102 | not invoke chdir between calls to getpwd. */ |
| 103 | pwd = p; |
| 104 | } |
| 105 | return p; |
| 106 | } |
| 107 | |
| 108 | #else /* VMS || _WIN32 && !__CYGWIN__ */ |
| 109 | |
| 110 | #ifndef MAXPATHLEN |
| 111 | #define MAXPATHLEN 255 |
| 112 | #endif |
| 113 | |
| 114 | char * |
| 115 | getpwd (void) |
| 116 | { |
| 117 | static char *pwd = 0; |
| 118 | |
| 119 | if (!pwd) |
| 120 | pwd = getcwd (XNEWVEC (char, MAXPATHLEN + 1), MAXPATHLEN + 1 |
| 121 | #ifdef VMS |
| 122 | , 0 |
| 123 | #endif |
| 124 | ); |
| 125 | return pwd; |
| 126 | } |
| 127 | |
| 128 | #endif /* VMS || _WIN32 && !__CYGWIN__ */ |