diff options
Diffstat (limited to 'gnu/usr.bin/cc/cc_int/getpwd.c')
-rw-r--r-- | gnu/usr.bin/cc/cc_int/getpwd.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/gnu/usr.bin/cc/cc_int/getpwd.c b/gnu/usr.bin/cc/cc_int/getpwd.c new file mode 100644 index 0000000..922a9ed --- /dev/null +++ b/gnu/usr.bin/cc/cc_int/getpwd.c @@ -0,0 +1,94 @@ +/* getpwd.c - get the working directory */ + +#include "config.h" + +#include <errno.h> +#include <sys/types.h> +#include <sys/stat.h> + +#ifndef errno +extern int errno; +#endif + +/* Virtually every UN*X system now in common use (except for pre-4.3-tahoe + BSD systems) now provides getcwd as called for by POSIX. Allow for + the few exceptions to the general rule here. */ + +#if !(defined (POSIX) || defined (USG) || defined (VMS)) +#include <sys/param.h> +extern char *getwd (); +#define getcwd(buf,len) getwd(buf) +#define GUESSPATHLEN (MAXPATHLEN + 1) +#else /* (defined (USG) || defined (VMS)) */ +extern char *getcwd (); +/* We actually use this as a starting point, not a limit. */ +#define GUESSPATHLEN 100 +#endif /* (defined (USG) || defined (VMS)) */ + +char *getenv (); +char *xmalloc (); + +#ifndef VMS + +/* Get the working directory. Use the PWD environment variable if it's + set correctly, since this is faster and gives more uniform answers + to the user. Yield the working directory if successful; otherwise, + yield 0 and set errno. */ + +char * +getpwd () +{ + static char *pwd; + static int failure_errno; + + char *p = pwd; + size_t s; + struct stat dotstat, pwdstat; + + if (!p && !(errno = failure_errno)) + { + if (! ((p = getenv ("PWD")) != 0 + && *p == '/' + && stat (p, &pwdstat) == 0 + && stat (".", &dotstat) == 0 + && dotstat.st_ino == pwdstat.st_ino + && dotstat.st_dev == pwdstat.st_dev)) + + /* The shortcut didn't work. Try the slow, ``sure'' way. */ + for (s = GUESSPATHLEN; ! getcwd (p = xmalloc (s), s); s *= 2) + { + int e = errno; + free (p); +#ifdef ERANGE + if (e != ERANGE) +#endif + { + errno = failure_errno = e; + p = 0; + break; + } + } + + /* Cache the result. This assumes that the program does + not invoke chdir between calls to getpwd. */ + pwd = p; + } + return p; +} + +#else /* VMS */ + +#ifndef MAXPATHLEN +#define MAXPATHLEN 255 +#endif + +char * +getpwd () +{ + static char *pwd = 0; + + if (!pwd) pwd = getcwd (xmalloc (MAXPATHLEN+1), MAXPATHLEN+1); + return pwd; +} + +#endif /* VMS */ |