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Arquivotheca.SunOS-4.1.4/lib/libc/gen/common/execvp.c
seta75D ff309bfe1c Init
2021-10-11 18:37:13 -03:00

109 lines
1.8 KiB
C

#if !defined(lint) && defined(SCCSIDS)
static char sccsid[] = "@(#)execvp.c 1.1 94/10/31 SMI"; /* from S5R2 1.2 */
#endif
/*LINTLIBRARY*/
/*
* execlp(name, arg,...,0) (like execl, but does path search)
* execvp(name, argv) (like execv, but does path search)
*/
#include <sys/errno.h>
#include <sys/param.h>
#include <varargs.h>
#define NULL 0
static char *execat();
static char *shell = "/bin/sh";
extern char *getenv(), *strchr();
extern unsigned sleep();
extern int errno, execv();
/*VARARGS1*/
int
execlp(name, va_alist)
char *name;
va_dcl
{
va_list args;
va_start(args);
return(execvp(name, (char **)args));
}
int
execvp(name, argv)
char *name, **argv;
{
char *pathstr;
char fname[MAXPATHLEN];
char *newargs[256];
int i;
register char *cp;
register unsigned etxtbsy=1;
register int eacces=0;
#ifdef POSIX
if (name[0] == 0) {
errno = ENOENT;
return (-1);
}
#endif POSIX
if((pathstr = getenv("PATH")) == NULL)
pathstr = ":/usr/ucb:/bin:/usr/bin";
cp = strchr(name, '/')? "": pathstr;
do {
cp = execat(cp, name, fname);
retry:
(void) 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);
}
}
(void) execv(shell, newargs);
return(-1);
case ETXTBSY:
if(++etxtbsy > 5)
return(-1);
(void) sleep(etxtbsy);
goto retry;
case EACCES:
++eacces;
break;
case ENOMEM:
case E2BIG:
case EFAULT:
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;
char *end;
s = si;
end = s + MAXPATHLEN;
while(*s1 && *s1 != ':' && s < end)
*s++ = *s1++;
if(si != s && s < end)
*s++ = '/';
while(*s2 && s < end)
*s++ = *s2++;
*s = '\0';
return(*s1? ++s1: 0);
}