newlib-cygwin/newlib/libc/posix/execvp.c

89 lines
1.8 KiB
C

/* execvp.c */
/* This and the other exec*.c files in this directory require
the target to provide the _execve syscall. */
#include <_ansi.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <ctype.h>
#ifdef __CYGWIN32__
static char path_delim;
#define PATH_DELIM path_delim
#else
#define PATH_DELIM ':'
#endif
/*
* Copy string, until c or <nul> is encountered.
* NUL-terminate the destination string (s1).
*/
static char *
_DEFUN (strccpy, (s1, s2, c),
char *s1 _AND
char *s2 _AND
char c)
{
char *dest = s1;
while (*s2 && *s2 != c)
*s1++ = *s2++;
*s1 = 0;
return dest;
}
int
_DEFUN (execvp, (file, argv),
_CONST char *file _AND
char * _CONST argv[])
{
char *path = getenv ("PATH");
char buf[MAXNAMLEN];
/* If $PATH doesn't exist, just pass FILE on unchanged. */
if (!path)
return execv (file, argv);
/* If FILE contains a directory, don't search $PATH. */
if (strchr (file, '/')
#ifdef __CYGWIN32__
|| strchr (file, '\\')
#endif
)
return execv (file, argv);
#ifdef __CYGWIN32__
/* If a drive letter is passed, the path is still an absolute one.
Technically this isn't true, but Cygwin is currently defined so
that it is. */
if ((isalpha (file[0]) && file[1] == ':')
|| file[0] == '\\')
return execv (file, argv);
#endif
#ifdef __CYGWIN32__
path_delim = cygwin_posix_path_list_p (path) ? ':' : ';';
#endif
while (*path)
{
strccpy (buf, path, PATH_DELIM);
/* An empty entry means the current directory. */
if (*buf != 0)
strcat (buf, "/");
strcat (buf, file);
if (execv (buf, argv) == -1 && errno != ENOENT)
return -1;
while (*path && *path != PATH_DELIM)
path++;
if (*path == PATH_DELIM)
path++; /* skip over delim */
}
return -1;
}