ref: 32172cdf6a00026675dee9be5c0fa3aef5fdff9d
dir: femtolisp/llt/dirpath.c
#ifdef __plan9__
#include <u.h>
#include <libc.h>
#else
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <sys/stat.h>
#include <sys/types.h>
#ifdef WIN32
#include <malloc.h>
#include <sys/timeb.h>
#include <windows.h>
#undef NO_ERROR
#undef MOD_SHIFT
#undef TRUE
#undef FALSE
#undef VOID
#else
#include <sys/time.h>
#include <sys/poll.h>
#include <unistd.h>
#endif
#endif
#include "dtypes.h"
#include "dirpath.h"
void get_cwd(char *buf, size_t size)
{
#ifdef __plan9__
getwd(buf, size);
#elif !defined(WIN32)
getcwd(buf, size);
#else
GetCurrentDirectory(size, buf);
#endif
}
int set_cwd(char *buf)
{
#ifndef WIN32
if (chdir(buf) == -1)
return 1;
#else
if (SetCurrentDirectory(buf) == 0)
return 1;
#endif
return 0;
}
// destructively convert path to directory part
void path_to_dirname(char *path)
{
char *sep = strrchr(path, PATHSEP);
if (sep != NULL) {
*sep = '\0';
}
else {
path[0] = '\0';
}
}
#ifdef __plan9__
char *get_exename(char *buf, size_t size)
{
snprint(buf, size, "/sys/lib/flisp/flisp");
return buf;
}
#elif defined(LINUX)
char *get_exename(char *buf, size_t size)
{
char linkname[64]; /* /proc/<pid>/exe */
pid_t pid;
ssize_t ret;
/* Get our PID and build the name of the link in /proc */
pid = getpid();
if (snprintf(linkname, sizeof(linkname), "/proc/%i/exe", pid) < 0)
return NULL;
/* Now read the symbolic link */
ret = readlink(linkname, buf, size);
/* In case of an error, leave the handling up to the caller */
if (ret == -1)
return NULL;
/* Report insufficient buffer size */
if ((size_t)ret >= size)
return NULL;
/* Ensure proper NUL termination */
buf[ret] = 0;
return buf;
}
#elif defined(OPENBSD)
#include <sys/param.h>
#include <sys/sysctl.h>
char *get_exename(char *buf, size_t size)
{
int mib[4];
pid_t pid;
size_t len, plen;
char **argv, **argv2;
char *p, *path, *pathcpy, filename[PATH_MAX];
struct stat sbuf;
pid = getpid();
mib[0] = CTL_KERN;
mib[1] = KERN_PROC_ARGS;
mib[2] = pid;
mib[3] = KERN_PROC_ARGV;
buf = NULL;
argv = NULL;
len = 128;
// Now, play The Guessing Game with sysctl(3) as to how big argv
// is supposed to be. (It's loads of fun for the whole family!)
while (len < SIZE_MAX / 2) {
len *= 2;
if ((argv2 = realloc(argv, len)) == NULL)
break;
argv = argv2;
if (sysctl(mib, 4, argv, &len, NULL, 0) == -1) {
if (errno == ENOMEM)
continue; // Go back and realloc more memory.
break; // Bail for some other error in sysctl(3).
}
// If you made it here, congrats! You guessed right!
if (*argv != NULL)
buf = strdup(*argv);
break;
}
free(argv);
// If no error occurred in the sysctl(3) KERN_PROC_ARGV call
// above, then buf at this point contains some kind of pathname.
if (buf != NULL) {
if (strchr(buf, '/') == NULL) {
// buf contains a `basename`-style pathname (i.e. "foo",
// as opposed to "../foo" or "/usr/bin/foo"); search the
// PATH for its location. (BTW the setgid(2), setuid(2)
// calls are a pre-condition for the access(2) call
// later.)
if ( (path = getenv("PATH")) != NULL &&
!setgid(getegid()) && !setuid(geteuid()) ) {
// The strdup(3) call below, if successful, will
// allocate memory for the PATH string returned by
// getenv(3) above. This is necessary because the man
// page of getenv(3) says that its return value
// "should be considered read-only"; however, the
// strsep(3) call below is going to be destructively
// modifying that value. ("Hulk smash!")
if ((path = strdup(path)) != NULL) {
pathcpy = path;
len = strlen(buf);
while ((p = strsep(&pathcpy, ":")) != NULL) {
if (*p == '\0') p = ".";
plen = strlen(p);
// strip trailing '/'
while (p[plen-1] == '/') p[--plen] = '\0';
if (plen + 1 + len < sizeof(filename)) {
snprintf(filename, sizeof(filename), "%s/%s", p, buf);
if ( (stat(filename, &sbuf) == 0) &&
S_ISREG(sbuf.st_mode) &&
access(filename, X_OK) == 0 ) {
buf = strdup(filename);
break;
}
}
}
free(path); // free the strdup(3) memory allocation.
}
}
else buf = NULL; // call to getenv(3) or [sg]ete?[ug]id(2) failed.
}
if ( buf != NULL && *buf != '/' ) {
// buf contains a relative pathname (e.g. "../foo");
// resolve this to an absolute pathname.
if ( strlcpy(filename, buf, sizeof(filename)) >= sizeof(filename) ||
realpath(filename, buf) == NULL )
buf = NULL;
}
}
return buf;
}
#elif defined(FREEBSD) || defined(NETBSD)
#include <sys/types.h>
#include <sys/sysctl.h>
char *get_exename(char *buf, size_t size)
{
int mib[4];
mib[0] = CTL_KERN;
#if defined(FREEBSD)
mib[1] = KERN_PROC;
mib[2] = KERN_PROC_PATHNAME;
mib[3] = -1;
#else
mib[1] = KERN_PROC_ARGS;
mib[2] = -1;
mib[3] = KERN_PROC_PATHNAME;
#endif
sysctl(mib, 4, buf, &size, NULL, 0);
return buf;
}
#elif defined(WIN32)
char *get_exename(char *buf, size_t size)
{
if (GetModuleFileName(NULL, buf, size) == 0)
return NULL;
return buf;
}
#elif defined(MACOSX)
#include <mach-o/dyld.h>
char *get_exename(char *buf, size_t size)
{
uint32_t bufsize = (uint32_t)size;
if (_NSGetExecutablePath(buf, &bufsize))
return NULL;
return buf;
}
#endif