forked from KolibriOS/kolibrios
192 lines
4.2 KiB
C
192 lines
4.2 KiB
C
/*
|
||
FUNCTION
|
||
<<system>>---execute command string
|
||
|
||
INDEX
|
||
system
|
||
INDEX
|
||
_system_r
|
||
|
||
ANSI_SYNOPSIS
|
||
#include <stdlib.h>
|
||
int system(char *<[s]>);
|
||
|
||
int _system_r(void *<[reent]>, char *<[s]>);
|
||
|
||
TRAD_SYNOPSIS
|
||
#include <stdlib.h>
|
||
int system(<[s]>)
|
||
char *<[s]>;
|
||
|
||
int _system_r(<[reent]>, <[s]>)
|
||
char *<[reent]>;
|
||
char *<[s]>;
|
||
|
||
DESCRIPTION
|
||
|
||
Use <<system>> to pass a command string <<*<[s]>>> to <</bin/sh>> on
|
||
your system, and wait for it to finish executing.
|
||
|
||
Use ``<<system(NULL)>>'' to test whether your system has <</bin/sh>>
|
||
available.
|
||
|
||
The alternate function <<_system_r>> is a reentrant version. The
|
||
extra argument <[reent]> is a pointer to a reentrancy structure.
|
||
|
||
RETURNS
|
||
<<system(NULL)>> returns a non-zero value if <</bin/sh>> is available, and
|
||
<<0>> if it is not.
|
||
|
||
With a command argument, the result of <<system>> is the exit status
|
||
returned by <</bin/sh>>.
|
||
|
||
PORTABILITY
|
||
ANSI C requires <<system>>, but leaves the nature and effects of a
|
||
command processor undefined. ANSI C does, however, specify that
|
||
<<system(NULL)>> return zero or nonzero to report on the existence of
|
||
a command processor.
|
||
|
||
POSIX.2 requires <<system>>, and requires that it invoke a <<sh>>.
|
||
Where <<sh>> is found is left unspecified.
|
||
|
||
Supporting OS subroutines required: <<_exit>>, <<_execve>>, <<_fork_r>>,
|
||
<<_wait_r>>.
|
||
*/
|
||
|
||
#include <_ansi.h>
|
||
#include <errno.h>
|
||
#include <stddef.h>
|
||
#include <stdlib.h>
|
||
#include <unistd.h>
|
||
#include <_syslist.h>
|
||
#include <reent.h>
|
||
|
||
#if defined (unix) || defined (__CYGWIN__)
|
||
static int _EXFUN(do_system, (struct _reent *ptr _AND _CONST char *s));
|
||
#endif
|
||
|
||
int
|
||
_DEFUN(_system_r, (ptr, s),
|
||
struct _reent *ptr _AND
|
||
_CONST char *s)
|
||
{
|
||
#if defined(HAVE_SYSTEM)
|
||
return _system (s);
|
||
ptr = ptr;
|
||
#elif defined(NO_EXEC)
|
||
if (s == NULL)
|
||
return 0;
|
||
errno = ENOSYS;
|
||
return -1;
|
||
#else
|
||
|
||
/* ??? How to handle (s == NULL) here is not exactly clear.
|
||
If _fork_r fails, that's not really a justification for returning 0.
|
||
For now we always return 0 and leave it to each target to explicitly
|
||
handle otherwise (this can always be relaxed in the future). */
|
||
|
||
#if defined (unix) || defined (__CYGWIN__)
|
||
if (s == NULL)
|
||
return 1;
|
||
return do_system (ptr, s);
|
||
#else
|
||
if (s == NULL)
|
||
return 0;
|
||
errno = ENOSYS;
|
||
return -1;
|
||
#endif
|
||
|
||
#endif
|
||
}
|
||
|
||
#ifndef _REENT_ONLY
|
||
|
||
int
|
||
_DEFUN(system, (s),
|
||
_CONST char *s)
|
||
{
|
||
return _system_r (_REENT, s);
|
||
}
|
||
|
||
#endif
|
||
|
||
#if defined (unix) && !defined (__CYGWIN__) && !defined(__rtems__)
|
||
extern char **environ;
|
||
|
||
/* Only deal with a pointer to environ, to work around subtle bugs with shared
|
||
libraries and/or small data systems where the user declares his own
|
||
'environ'. */
|
||
static char ***p_environ = &environ;
|
||
|
||
static int
|
||
_DEFUN(do_system, (ptr, s),
|
||
struct _reent *ptr _AND
|
||
_CONST char *s)
|
||
{
|
||
char *argv[4];
|
||
int pid, status;
|
||
|
||
argv[0] = "sh";
|
||
argv[1] = "-c";
|
||
argv[2] = (char *) s;
|
||
argv[3] = NULL;
|
||
|
||
if ((pid = _fork_r (ptr)) == 0)
|
||
{
|
||
_execve ("/bin/sh", argv, *p_environ);
|
||
exit (100);
|
||
}
|
||
else if (pid == -1)
|
||
return -1;
|
||
else
|
||
{
|
||
int rc = _wait_r (ptr, &status);
|
||
if (rc == -1)
|
||
return -1;
|
||
status = (status >> 8) & 0xff;
|
||
return status;
|
||
}
|
||
}
|
||
#endif
|
||
|
||
#if defined (__CYGWIN__)
|
||
static int
|
||
_DEFUN(do_system, (ptr, s),
|
||
struct _reent *ptr _AND
|
||
_CONST char *s)
|
||
{
|
||
char *argv[4];
|
||
int pid, status;
|
||
|
||
argv[0] = "sh";
|
||
argv[1] = "-c";
|
||
argv[2] = (char *) s;
|
||
argv[3] = NULL;
|
||
|
||
if ((pid = vfork ()) == 0)
|
||
{
|
||
/* ??? It's not clear what's the right path to take (pun intended :-).
|
||
There won't be an "sh" in any fixed location so we need each user
|
||
to be able to say where to find "sh". That suggests using an
|
||
environment variable, but after a few more such situations we may
|
||
have too many of them. */
|
||
char *sh = getenv ("SH_PATH");
|
||
if (sh == NULL)
|
||
sh = "/bin/sh";
|
||
_execve (sh, argv, environ);
|
||
exit (100);
|
||
}
|
||
else if (pid == -1)
|
||
return -1;
|
||
else
|
||
{
|
||
extern int _wait (int *);
|
||
int rc = _wait (&status);
|
||
if (rc == -1)
|
||
return -1;
|
||
status = (status >> 8) & 0xff;
|
||
return status;
|
||
}
|
||
}
|
||
#endif
|