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

/* @(#)exec.c	4.1 (Berkeley) %G% */
/*
 *	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
a69e788c BJ	1	/* @(#)exec.c 4.1 (Berkeley) %G% */
	2	/*
	3	* execlp(name, arg,...,0) (like execl, but does path search)
	4	* execvp(name, argv) (like execv, but does path search)
	5	*/
	6	#include <errno.h>
	7	#define NULL 0
	8
	9	static char shell[] = "/bin/sh";
	10	char execat(), getenv();
	11	extern errno;
	12
	13	execlp(name, argv)
	14	char name, argv;
	15	{
	16	return(execvp(name, &argv));
	17	}
	18
	19	execvp(name, argv)
	20	char name, *argv;
	21	{
	22	char *pathstr;
	23	register char *cp;
	24	char fname[128];
	25	char *newargs[256];
	26	int i;
	27	register unsigned etxtbsy = 1;
	28	register eacces = 0;
	29
	30	if ((pathstr = getenv("PATH")) == NULL)
	31	pathstr = ":/bin:/usr/bin";
	32	cp = index(name, '/')? "": pathstr;
	33
	34	do {
	35	cp = execat(cp, name, fname);
	36	retry:
	37	execv(fname, argv);
	38	switch(errno) {
	39	case ENOEXEC:
	40	newargs[0] = "sh";
	41	newargs[1] = fname;
	42	for (i=1; newargs[i+1]=argv[i]; i++) {
	43	if (i>=254) {
	44	errno = E2BIG;
	45	return(-1);
	46	}
	47	}
	48	execv(shell, newargs);
	49	return(-1);
	50	case ETXTBSY:
	51	if (++etxtbsy > 5)
	52	return(-1);
	53	sleep(etxtbsy);
	54	goto retry;
	55	case EACCES:
	56	eacces++;
	57	break;
	58	case ENOMEM:
	59	case E2BIG:
	60	return(-1);
	61	}
	62	} while (cp);
	63	if (eacces)
	64	errno = EACCES;
65	return(-1);
66	}
67
68	static char *
69	execat(s1, s2, si)
70	register char s1, s2;
71	char *si;
72	{
73	register char *s;
74
75	s = si;
76	while (s1 && s1 != ':' && *s1 != '-')
77	s++ = s1++;
78	if (si != s)
79	*s++ = '/';
80	while (*s2)
81	s++ = s2++;
82	*s = '\0';
83	return(*s1? ++s1: 0);
84	}