[unix-history] / usr / src / lib / libc / gen / exec.c

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)exec.c	5.2 (Berkeley) %G%";
#endif LIBC_SCCS and not lint

/*
 *	execlp(name, arg,...,0)	(like execl, but does path search)
 *	execvp(name, argv)	(like execv, but does path search)
 */
#include <errno.h>
#define	NULL	0

static	char shell[] =	"/bin/sh";
char	*execat(), *getenv();
extern	errno;

execlp(name, argv)
char *name, *argv;
{
	return(execvp(name, &argv));
}

execvp(name, argv)
char *name, **argv;
{
	char *pathstr;
	register char *cp;
	char fname[128];
	char *newargs[256];
	int i;
	register unsigned etxtbsy = 1;
	register eacces = 0;

	if ((pathstr = getenv("PATH")) == NULL)
		pathstr = ":/bin:/usr/bin";
	cp = index(name, '/')? "": pathstr;

	do {
		cp = execat(cp, name, fname);
	retry:
		execv(fname, argv);
		switch(errno) {
		case ENOEXEC:
			newargs[0] = "sh";
			newargs[1] = fname;
			for (i=1; newargs[i+1]=argv[i]; i++) {
				if (i>=254) {
					errno = E2BIG;
					return(-1);
				}
			}
			execv(shell, newargs);
			return(-1);
		case ETXTBSY:
			if (++etxtbsy > 5)
				return(-1);
			sleep(etxtbsy);
			goto retry;
		case EACCES:
			eacces++;
			break;
		case ENOMEM:
		case E2BIG:
			return(-1);
		}
	} while (cp);
	if (eacces)
		errno = EACCES;
	return(-1);
}

static char *
execat(s1, s2, si)
register char *s1, *s2;
char *si;
{
	register char *s;

	s = si;
	while (*s1 && *s1 != ':')
		*s++ = *s1++;
	if (si != s)
		*s++ = '/';
	while (*s2)
		*s++ = *s2++;
	*s = '\0';
	return(*s1? ++s1: 0);
}
Commit	Line	Data
2ce81398 DS	1	#if defined(LIBC_SCCS) && !defined(lint)
	2	static char sccsid[] = "@(#)exec.c 5.2 (Berkeley) %G%";
	3	#endif LIBC_SCCS and not lint
b8f253e8	4
a69e788c BJ	5	/*
	6	* execlp(name, arg,...,0) (like execl, but does path search)
	7	* execvp(name, argv) (like execv, but does path search)
	8	*/
	9	#include <errno.h>
	10	#define NULL 0
	11
	12	static char shell[] = "/bin/sh";
	13	char execat(), getenv();
	14	extern errno;
	15
	16	execlp(name, argv)
	17	char name, argv;
	18	{
	19	return(execvp(name, &argv));
	20	}
	21
	22	execvp(name, argv)
	23	char name, *argv;
	24	{
	25	char *pathstr;
	26	register char *cp;
	27	char fname[128];
	28	char *newargs[256];
	29	int i;
	30	register unsigned etxtbsy = 1;
	31	register eacces = 0;
	32
	33	if ((pathstr = getenv("PATH")) == NULL)
	34	pathstr = ":/bin:/usr/bin";
	35	cp = index(name, '/')? "": pathstr;
	36
	37	do {
	38	cp = execat(cp, name, fname);
	39	retry:
	40	execv(fname, argv);
	41	switch(errno) {
	42	case ENOEXEC:
	43	newargs[0] = "sh";
	44	newargs[1] = fname;
	45	for (i=1; newargs[i+1]=argv[i]; i++) {
	46	if (i>=254) {
	47	errno = E2BIG;
	48	return(-1);
	49	}
	50	}
	51	execv(shell, newargs);
	52	return(-1);
	53	case ETXTBSY:
	54	if (++etxtbsy > 5)
	55	return(-1);
	56	sleep(etxtbsy);
	57	goto retry;
	58	case EACCES:
	59	eacces++;
	60	break;
	61	case ENOMEM:
	62	case E2BIG:
	63	return(-1);
	64	}
	65	} while (cp);
	66	if (eacces)
	67	errno = EACCES;
	68	return(-1);
69	}
70
71	static char *
72	execat(s1, s2, si)
73	register char s1, s2;
74	char *si;
75	{
76	register char *s;
77
78	s = si;
42351701	79	while (s1 && s1 != ':')
a69e788c BJ	80	s++ = s1++;
	81	if (si != s)
	82	*s++ = '/';
	83	while (*s2)
	84	s++ = s2++;
	85	*s = '\0';
	86	return(*s1? ++s1: 0);
	87	}