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

/*
 *	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 != ':' && *s1 != '-')
		*s++ = *s1++;
	if (si != s)
		*s++ = '/';
	while (*s2)
		*s++ = *s2++;
	*s = '\0';
	return(*s1? ++s1: 0);
}
Commit	Line	Data
74bfa9a8 DR	1	/*
	2	* execlp(name, arg,...,0) (like execl, but does path search)
	3	* execvp(name, argv) (like execv, but does path search)
	4	*/
	5	#include <errno.h>
	6	#define NULL 0
	7
	8	static char shell[] = "/bin/sh";
	9	char execat(), getenv();
	10	extern errno;
	11
	12	execlp(name, argv)
	13	char name, argv;
	14	{
	15	return(execvp(name, &argv));
	16	}
	17
	18	execvp(name, argv)
	19	char name, *argv;
	20	{
	21	char *pathstr;
	22	register char *cp;
	23	char fname[128];
	24	char *newargs[256];
	25	int i;
	26	register unsigned etxtbsy = 1;
	27	register eacces = 0;
	28
	29	if ((pathstr = getenv("PATH")) == NULL)
	30	pathstr = ":/bin:/usr/bin";
	31	cp = index(name, '/')? "": pathstr;
	32
	33	do {
	34	cp = execat(cp, name, fname);
	35	retry:
	36	execv(fname, argv);
	37	switch(errno) {
	38	case ENOEXEC:
	39	newargs[0] = "sh";
	40	newargs[1] = fname;
	41	for (i=1; newargs[i+1]=argv[i]; i++) {
	42	if (i>=254) {
	43	errno = E2BIG;
	44	return(-1);
	45	}
	46	}
	47	execv(shell, newargs);
	48	return(-1);
	49	case ETXTBSY:
	50	if (++etxtbsy > 5)
	51	return(-1);
	52	sleep(etxtbsy);
	53	goto retry;
	54	case EACCES:
	55	eacces++;
	56	break;
	57	case ENOMEM:
	58	case E2BIG:
	59	return(-1);
	60	}
	61	} while (cp);
	62	if (eacces)
	63	errno = EACCES;
	64	return(-1);
65	}
66
67	static char *
68	execat(s1, s2, si)
69	register char s1, s2;
70	char *si;
71	{
72	register char *s;
73
74	s = si;
75	while (s1 && s1 != ':' && *s1 != '-')
76	s++ = s1++;
77	if (si != s)
78	*s++ = '/';
79	while (*s2)
80	s++ = s2++;
81	*s = '\0';
82	return(*s1? ++s1: 0);
83	}