NetBSD-5.0.2/bin/csh/exec.c
/* $NetBSD: exec.c,v 1.27 2007/12/15 19:44:37 perry Exp $ */
/*-
* Copyright (c) 1980, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)exec.c 8.3 (Berkeley) 5/23/95";
#else
__RCSID("$NetBSD: exec.c,v 1.27 2007/12/15 19:44:37 perry Exp $");
#endif
#endif /* not lint */
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "csh.h"
#include "extern.h"
/*
* System level search and execute of a command. We look in each directory
* for the specified command name. If the name contains a '/' then we
* execute only the full path name. If there is no search path then we
* execute only full path names.
*/
extern char **environ;
/*
* As we search for the command we note the first non-trivial error
* message for presentation to the user. This allows us often
* to show that a file has the wrong mode/no access when the file
* is not in the last component of the search path, so we must
* go on after first detecting the error.
*/
static const char *exerr; /* Execution error message */
static Char *expath; /* Path for exerr */
/*
* Xhash is an array of HSHSIZ bits (HSHSIZ / 8 chars), which are used
* to hash execs. If it is allocated (havhash true), then to tell
* whether ``name'' is (possibly) present in the i'th component
* of the variable path, you look at the bit in xhash indexed by
* hash(hashname("name"), i). This is setup automatically
* after .login is executed, and recomputed whenever ``path'' is
* changed.
* The two part hash function is designed to let texec() call the
* more expensive hashname() only once and the simple hash() several
* times (once for each path component checked).
* Byte size is assumed to be 8.
*/
#define HSHSIZ 8192 /* 1k bytes */
#define HSHMASK (HSHSIZ - 1)
#define HSHMUL 243
static char xhash[HSHSIZ / 8];
#define hash(a, b) (((a) * HSHMUL + (b)) & HSHMASK)
#define bit(h, b) ((h)[(b) >> 3] & 1 << ((b) & 7)) /* bit test */
#define bis(h, b) ((h)[(b) >> 3] |= 1 << ((b) & 7)) /* bit set */
static int hits, misses;
/* Dummy search path for just absolute search when no path */
static Char *justabs[] = {STRNULL, 0};
static void pexerr(void) __dead;
static void texec(Char *, Char **);
static int hashname(Char *);
static int tellmewhat(struct wordent *, Char *);
static int executable(Char *, Char *, int);
static int iscommand(Char *);
void
/*ARGSUSED*/
doexec(Char **v, struct command *t)
{
struct varent *pathv;
Char *blk[2], **av, *dp, **pv, *sav;
int i, hashval, hashval1;
sigset_t nsigset;
int slash;
hashval = 0;
/*
* Glob the command name. We will search $path even if this does something,
* as in sh but not in csh. One special case: if there is no PATH, then we
* execute only commands which start with '/'.
*/
blk[0] = t->t_dcom[0];
blk[1] = 0;
gflag = 0, tglob(blk);
if (gflag) {
pv = globall(blk);
if (pv == 0) {
setname(vis_str(blk[0]));
stderror(ERR_NAME | ERR_NOMATCH);
}
gargv = 0;
}
else
pv = saveblk(blk);
trim(pv);
exerr = 0;
expath = Strsave(pv[0]);
Vexpath = expath;
pathv = adrof(STRpath);
if (pathv == 0 && expath[0] != '/') {
blkfree(pv);
pexerr();
}
slash = any(short2str(expath), '/');
/*
* Glob the argument list, if necessary. Otherwise trim off the quote bits.
*/
gflag = 0;
av = &t->t_dcom[1];
tglob(av);
if (gflag) {
av = globall(av);
if (av == 0) {
blkfree(pv);
setname(vis_str(expath));
stderror(ERR_NAME | ERR_NOMATCH);
}
gargv = 0;
}
else
av = saveblk(av);
blkfree(t->t_dcom);
t->t_dcom = blkspl(pv, av);
xfree((ptr_t) pv);
xfree((ptr_t) av);
av = t->t_dcom;
trim(av);
if (*av == NULL || **av == '\0')
pexerr();
xechoit(av); /* Echo command if -x */
/*
* Since all internal file descriptors are set to close on exec, we don't
* need to close them explicitly here. Just reorient ourselves for error
* messages.
*/
SHIN = 0;
SHOUT = 1;
SHERR = 2;
OLDSTD = 0;
/*
* We must do this AFTER any possible forking (like `foo` in glob) so that
* this shell can still do subprocesses.
*/
sigemptyset(&nsigset);
(void)sigprocmask(SIG_SETMASK, &nsigset, NULL);
/*
* If no path, no words in path, or a / in the filename then restrict the
* command search.
*/
if (pathv == 0 || pathv->vec[0] == 0 || slash)
pv = justabs;
else
pv = pathv->vec;
sav = Strspl(STRslash, *av); /* / command name for postpending */
Vsav = sav;
if (havhash)
hashval = hashname(*av);
i = 0;
hits++;
do {
/*
* Try to save time by looking at the hash table for where this command
* could be. If we are doing delayed hashing, then we put the names in
* one at a time, as the user enters them. This is kinda like Korn
* Shell's "tracked aliases".
*/
if (!slash && pv[0][0] == '/' && havhash) {
hashval1 = hash(hashval, i);
if (!bit(xhash, hashval1))
goto cont;
}
if (pv[0][0] == 0 || eq(pv[0], STRdot)) /* don't make ./xxx */
texec(*av, av);
else {
dp = Strspl(*pv, sav);
Vdp = dp;
texec(dp, av);
Vdp = 0;
xfree((ptr_t)dp);
}
misses++;
cont:
pv++;
i++;
} while (*pv);
hits--;
Vsav = 0;
xfree((ptr_t)sav);
pexerr();
/* NOTREACHED */
}
static void
pexerr(void)
{
/* Couldn't find the damn thing */
if (expath) {
setname(vis_str(expath));
Vexpath = 0;
xfree((ptr_t)expath);
expath = 0;
}
else
setname("");
if (exerr)
stderror(ERR_NAME | ERR_STRING, exerr);
else
stderror(ERR_NAME | ERR_COMMAND);
/* NOTREACHED */
}
/*
* Execute command f, arg list t.
* Record error message if not found.
* Also do shell scripts here.
*/
static void
texec(Char *sf, Char **st)
{
struct varent *v;
Char *lastsh[2], **vp, *st0, **ost;
char *f, **t;
int fd;
unsigned char c = '\0';
/* The order for the conversions is significant */
t = short2blk(st);
f = short2str(sf);
Vt = t;
errno = 0; /* don't use a previous error */
(void)execve(f, t, environ);
Vt = 0;
blkfree((Char **)t);
switch (errno) {
case ENOEXEC:
/*
* From: casper@fwi.uva.nl (Casper H.S. Dik) If we could not execute
* it, don't feed it to the shell if it looks like a binary!
*/
if ((fd = open(f, O_RDONLY)) != -1) {
if (read(fd, (char *)&c, 1) == 1) {
if (!Isprint(c) && (c != '\n' && c != '\t')) {
(void)close(fd);
/*
* We *know* what ENOEXEC means.
*/
stderror(ERR_ARCH, f, strerror(errno));
}
}
#ifdef _PATH_BSHELL
else
c = '#';
#endif
(void)close(fd);
}
/*
* If there is an alias for shell, then put the words of the alias in
* front of the argument list replacing the command name. Note no
* interpretation of the words at this point.
*/
v = adrof1(STRshell, &aliases);
if (v == 0) {
vp = lastsh;
vp[0] = adrof(STRshell) ? value(STRshell) : STR_SHELLPATH;
vp[1] = NULL;
#ifdef _PATH_BSHELL
if (fd != -1 && c != '#')
vp[0] = STR_BSHELL;
#endif
}
else
vp = v->vec;
st0 = st[0];
st[0] = sf;
ost = st;
st = blkspl(vp, st); /* Splice up the new arglst */
ost[0] = st0;
sf = *st;
/* The order for the conversions is significant */
t = short2blk(st);
f = short2str(sf);
xfree((ptr_t) st);
Vt = t;
(void)execve(f, t, environ);
Vt = 0;
blkfree((Char **) t);
/* FALLTHROUGH */
case ENOMEM:
stderror(ERR_SYSTEM, f, strerror(errno));
/* NOTREACHED */
case ENOENT:
break;
default:
if (exerr == 0) {
exerr = strerror(errno);
if (expath)
xfree((ptr_t) expath);
expath = Strsave(sf);
Vexpath = expath;
}
}
}
/*ARGSUSED*/
void
execash(Char **t, struct command *kp)
{
jmp_buf osetexit;
sig_t osigint, osigquit, osigterm;
int my_reenter, odidfds, oOLDSTD, oSHERR, oSHIN, oSHOUT;
int saveDIAG, saveIN, saveOUT, saveSTD;
if (chkstop == 0 && setintr)
panystop(0);
/*
* Hmm, we don't really want to do that now because we might
* fail, but what is the choice
*/
rechist();
osigint = signal(SIGINT, parintr);
osigquit = signal(SIGQUIT, parintr);
osigterm = signal(SIGTERM, parterm);
odidfds = didfds;
oSHIN = SHIN;
oSHOUT = SHOUT;
oSHERR = SHERR;
oOLDSTD = OLDSTD;
saveIN = dcopy(SHIN, -1);
saveOUT = dcopy(SHOUT, -1);
saveDIAG = dcopy(SHERR, -1);
saveSTD = dcopy(OLDSTD, -1);
lshift(kp->t_dcom, 1);
getexit(osetexit);
if ((my_reenter = setexit()) == 0) {
SHIN = dcopy(0, -1);
SHOUT = dcopy(1, -1);
SHERR = dcopy(2, -1);
didfds = 0;
doexec(t, kp);
}
(void)signal(SIGINT, osigint);
(void)signal(SIGQUIT, osigquit);
(void)signal(SIGTERM, osigterm);
doneinp = 0;
didfds = odidfds;
(void)close(SHIN);
(void)close(SHOUT);
(void)close(SHERR);
(void)close(OLDSTD);
SHIN = dmove(saveIN, oSHIN);
SHOUT = dmove(saveOUT, oSHOUT);
SHERR = dmove(saveDIAG, oSHERR);
OLDSTD = dmove(saveSTD, oOLDSTD);
resexit(osetexit);
if (my_reenter)
stderror(ERR_SILENT);
}
void
xechoit(Char **t)
{
if (adrof(STRecho)) {
int odidfds = didfds;
(void)fflush(csherr);
odidfds = didfds;
didfds = 0;
blkpr(csherr, t);
(void)fputc('\n', csherr);
(void)fflush(csherr);
didfds = odidfds;
}
}
void
/*ARGSUSED*/
dohash(Char **v, struct command *t)
{
struct dirent *dp;
struct varent *pathv;
DIR *dirp;
Char **pv;
int cnt, hashval, i;
i = 0;
havhash = 1;
pathv = adrof(STRpath);
for (cnt = 0; cnt < sizeof xhash; cnt++)
xhash[cnt] = 0;
if (pathv == 0)
return;
for (pv = pathv->vec; *pv; pv++, i++) {
if (pv[0][0] != '/')
continue;
dirp = opendir(short2str(*pv));
if (dirp == NULL)
continue;
while ((dp = readdir(dirp)) != NULL) {
if (dp->d_ino == 0)
continue;
if (dp->d_name[0] == '.' &&
(dp->d_name[1] == '\0' ||
(dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
continue;
hashval = hash(hashname(str2short(dp->d_name)), i);
bis(xhash, hashval);
/* tw_add_comm_name (dp->d_name); */
}
(void) closedir(dirp);
}
}
void
/*ARGSUSED*/
dounhash(Char **v, struct command *t)
{
havhash = 0;
}
void
/*ARGSUSED*/
hashstat(Char **v, struct command *t)
{
if (hits + misses)
(void)fprintf(cshout, "%d hits, %d misses, %d%%\n",
hits, misses, 100 * hits / (hits + misses));
}
/*
* Hash a command name.
*/
static int
hashname(Char *cp)
{
long h = 0;
while (*cp)
h = hash(h, *cp++);
return ((int) h);
}
static int
iscommand(Char *name)
{
struct varent *v;
Char **pv, *sav;
int hashval, hashval1, i;
int slash;
hashval = 0;
slash = any(short2str(name), '/');
v = adrof(STRpath);
if (v == 0 || v->vec[0] == 0 || slash)
pv = justabs;
else
pv = v->vec;
sav = Strspl(STRslash, name); /* / command name for postpending */
if (havhash)
hashval = hashname(name);
i = 0;
do {
if (!slash && pv[0][0] == '/' && havhash) {
hashval1 = hash(hashval, i);
if (!bit(xhash, hashval1))
goto cont;
}
if (pv[0][0] == 0 || eq(pv[0], STRdot)) { /* don't make ./xxx */
if (executable(NULL, name, 0)) {
xfree((ptr_t) sav);
return i + 1;
}
}
else {
if (executable(*pv, sav, 0)) {
xfree((ptr_t) sav);
return i + 1;
}
}
cont:
pv++;
i++;
} while (*pv);
xfree((ptr_t) sav);
return 0;
}
/* Also by:
* Andreas Luik <luik@isaak.isa.de>
* I S A GmbH - Informationssysteme fuer computerintegrierte Automatisierung
* Azenberstr. 35
* D-7000 Stuttgart 1
* West-Germany
* is the executable() routine below and changes to iscommand().
* Thanks again!!
*/
/*
* executable() examines the pathname obtained by concatenating dir and name
* (dir may be NULL), and returns 1 either if it is executable by us, or
* if dir_ok is set and the pathname refers to a directory.
* This is a bit kludgy, but in the name of optimization...
*/
static int
executable(Char *dir, Char *name, int dir_ok)
{
struct stat stbuf;
Char path[MAXPATHLEN + 1], *dp, *sp;
char *strname;
if (dir && *dir) {
for (dp = path, sp = dir; *sp; *dp++ = *sp++)
if (dp == &path[MAXPATHLEN + 1]) {
*--dp = '\0';
break;
}
for (sp = name; *sp; *dp++ = *sp++)
if (dp == &path[MAXPATHLEN + 1]) {
*--dp = '\0';
break;
}
*dp = '\0';
strname = short2str(path);
}
else
strname = short2str(name);
return (stat(strname, &stbuf) != -1 && ((S_ISREG(stbuf.st_mode) &&
/* save time by not calling access() in the hopeless case */
(stbuf.st_mode & (S_IXOTH | S_IXGRP | S_IXUSR)) &&
access(strname, X_OK) == 0) || (dir_ok && S_ISDIR(stbuf.st_mode))));
}
/* The dowhich() is by:
* Andreas Luik <luik@isaak.isa.de>
* I S A GmbH - Informationssysteme fuer computerintegrierte Automatisierung
* Azenberstr. 35
* D-7000 Stuttgart 1
* West-Germany
* Thanks!!
*/
/*ARGSUSED*/
void
dowhich(Char **v, struct command *c)
{
struct wordent lexw[3];
struct varent *vp;
lexw[0].next = &lexw[1];
lexw[1].next = &lexw[2];
lexw[2].next = &lexw[0];
lexw[0].prev = &lexw[2];
lexw[1].prev = &lexw[0];
lexw[2].prev = &lexw[1];
lexw[0].word = STRNULL;
lexw[2].word = STRret;
while (*++v) {
if ((vp = adrof1(*v, &aliases)) != NULL) {
(void)fprintf(cshout, "%s: \t aliased to ", vis_str(*v));
blkpr(cshout, vp->vec);
(void)fputc('\n', cshout);
set(STRstatus, Strsave(STR0));
}
else {
lexw[1].word = *v;
set(STRstatus, Strsave(tellmewhat(lexw, NULL) ? STR0 : STR1));
}
}
}
static int
tellmewhat(struct wordent *lexp, Char *str)
{
struct biltins *bptr;
struct wordent *sp;
Char *cmd, *s0, *s1, *s2;
int i;
int aliased, found;
Char qc;
aliased = 0;
sp = lexp->next;
if (adrof1(sp->word, &aliases)) {
alias(lexp);
sp = lexp->next;
aliased = 1;
}
s0 = sp->word; /* to get the memory freeing right... */
/* handle quoted alias hack */
if ((*(sp->word) & (QUOTE | TRIM)) == QUOTE)
(sp->word)++;
/* do quoting, if it hasn't been done */
s1 = s2 = sp->word;
while (*s2)
switch (*s2) {
case '\'':
case '"':
qc = *s2++;
while (*s2 && *s2 != qc)
*s1++ = *s2++ | QUOTE;
if (*s2)
s2++;
break;
case '\\':
if (*++s2)
*s1++ = *s2++ | QUOTE;
break;
default:
*s1++ = *s2++;
}
*s1 = '\0';
for (bptr = bfunc; bptr < &bfunc[nbfunc]; bptr++) {
if (eq(sp->word, str2short(bptr->bname))) {
if (str == NULL) {
if (aliased)
prlex(cshout, lexp);
(void)fprintf(cshout, "%s: shell built-in command.\n",
vis_str(sp->word));
}
else
(void)Strcpy(str, sp->word);
sp->word = s0; /* we save and then restore this */
return 1;
}
}
sp->word = cmd = globone(sp->word, G_IGNORE);
if ((i = iscommand(sp->word)) != 0) {
Char **pv;
struct varent *v;
int slash = any(short2str(sp->word), '/');
v = adrof(STRpath);
if (v == 0 || v->vec[0] == 0 || slash)
pv = justabs;
else
pv = v->vec;
while (--i)
pv++;
if (pv[0][0] == 0 || eq(pv[0], STRdot)) {
if (!slash) {
sp->word = Strspl(STRdotsl, sp->word);
prlex(cshout, lexp);
xfree((ptr_t) sp->word);
}
else
prlex(cshout, lexp);
}
else {
s1 = Strspl(*pv, STRslash);
sp->word = Strspl(s1, sp->word);
xfree((ptr_t) s1);
if (str == NULL)
prlex(cshout, lexp);
else
(void)Strcpy(str, sp->word);
xfree((ptr_t) sp->word);
}
found = 1;
}
else {
if (str == NULL) {
if (aliased)
prlex(cshout, lexp);
(void)fprintf(csherr,
"%s: Command not found.\n", vis_str(sp->word));
}
else
(void)Strcpy(str, sp->word);
found = 0;
}
sp->word = s0; /* we save and then restore this */
xfree((ptr_t) cmd);
return found;
}