2.11BSD/src/bin/tcsh/sh.exec.c
/* $Header: /home/hyperion/mu/christos/src/sys/tcsh-6.00/RCS/sh.exec.c,v 3.0 1991/07/04 21:49:28 christos Exp $ */
/*
* sh.exec.c: Search, find, and execute a command!
*/
/*-
* Copyright (c) 1980, 1991 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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 "config.h"
#if !defined(lint) && !defined(pdp11)
static char *rcsid()
{ return "$Id: sh.exec.c,v 3.0 1991/07/04 21:49:28 christos Exp $"; }
#endif
#include "sh.h"
#include "tw.h"
/*
* C shell
*/
/*
* 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.
*/
/*
* 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 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 */
#ifdef VFORK
static int hits, misses;
#endif
/* Dummy search path for just absolute search when no path */
static Char *justabs[] = {STRNULL, 0};
static void pexerr __P((void));
static void texec __P((Char *, Char **));
static int hashname __P((Char *));
void
doexec(t)
register struct command *t;
{
register Char *dp, **pv, **av, *sav;
register struct varent *v;
register bool slash;
register int hshval = 0, hshval1, i;
Char *blk[2];
/*
* 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(short2str(blk[0]));
stderror(ERR_NAME | ERR_NOMATCH);
}
gargv = 0;
}
else
pv = saveblk(blk);
trim(pv);
exerr = 0;
expath = Strsave(pv[0]);
#ifdef VFORK
Vexpath = expath;
#endif
v = adrof(STRpath);
if (v == 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(short2str(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 */
#ifdef FIOCLEX
/*
* 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;
SHDIAG = 2;
OLDSTD = 0;
isoutatty = isatty(SHOUT);
isdiagatty = isatty(SHDIAG);
#else
closech(); /* Close random fd's */
#endif
/*
* We must do this AFTER any possible forking (like `foo` in glob) so that
* this shell can still do subprocesses.
*/
#ifdef BSDSIGS
(void) sigsetmask((sigmask_t) 0);
#else /* BSDSIGS */
(void) sigrelse(SIGINT);
(void) sigrelse(SIGCHLD);
#endif /* BSDSIGS */
/*
* If no path, no words in path, or a / in the filename then restrict the
* command search.
*/
if (v == 0 || v->vec[0] == 0 || slash)
pv = justabs;
else
pv = v->vec;
sav = Strspl(STRslash, *av);/* / command name for postpending */
#ifdef VFORK
Vsav = sav;
#endif
if (havhash)
hshval = hashname(*av);
i = 0;
#ifdef VFORK
hits++;
#endif
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) {
hshval1 = hash(hshval, i);
if (!bit(xhash, hshval1))
goto cont;
}
if (pv[0][0] == 0 || eq(pv[0], STRdot)) /* don't make ./xxx */
texec(*av, av);
else {
dp = Strspl(*pv, sav);
#ifdef VFORK
Vdp = dp;
#endif
texec(dp, av);
#ifdef VFORK
Vdp = 0;
#endif
xfree((ptr_t) dp);
}
#ifdef VFORK
misses++;
#endif
cont:
pv++;
i++;
} while (*pv);
#ifdef VFORK
hits--;
#endif
#ifdef VFORK
Vsav = 0;
#endif
xfree((ptr_t) sav);
pexerr();
}
static void
pexerr()
{
/* Couldn't find the damn thing */
if (expath) {
setname(short2str(expath));
#ifdef VFORK
Vexpath = 0;
#endif
xfree((ptr_t) expath);
expath = 0;
}
else
setname("");
if (exerr)
stderror(ERR_NAME | ERR_STRING, exerr);
stderror(ERR_NAME | ERR_COMMAND);
}
/*
* Execute command f, arg list t.
* Record error message if not found.
* Also do shell scripts here.
*/
static void
texec(sf, st)
Char *sf;
register Char **st;
{
register char **t;
register char *f;
register struct varent *v;
register Char **vp;
Char *lastsh[2];
int fd;
unsigned char c;
Char *st0, **ost;
/* The order for the conversions is significant */
t = short2blk(st);
f = short2str(sf);
#ifdef VFORK
Vt = t;
#endif
errno = 0; /* don't use a previous error */
#ifdef apollo
/*
* If we try to execute an nfs mounted directory on the apollo, we
* hang forever. So until apollo fixes that..
*/
{
struct stat stb;
if (stat(f, &stb) == 0 && S_ISDIR(stb.st_mode))
errno = EISDIR;
}
if (errno == 0)
#endif
(void) execv(f, t);
#ifdef VFORK
Vt = 0;
#endif
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] = NOSTR;
#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);
#ifdef VFORK
Vt = t;
#endif
(void) execv(f, t);
#ifdef VFORK
Vt = 0;
#endif
blkfree((Char **) t);
/* The sky is falling, the sky is falling! */
case ENOMEM:
stderror(ERR_SYSTEM, f, strerror(errno));
#ifdef _IBMR2
case 0: /* execv fails and returns 0! */
#endif /* _IBMR2 */
case ENOENT:
break;
default:
if (exerr == 0) {
exerr = strerror(errno);
if (expath)
xfree((ptr_t) expath);
expath = Strsave(sf);
#ifdef VFORK
Vexpath = expath;
#endif
}
}
}
/*ARGSUSED*/
void
execash(t, kp)
char **t;
register struct command *kp;
{
if (chkstop == 0 && setintr)
panystop(0);
#ifdef notdef
/*
* Why we don't want to close SH* on exec? I think we do... Christos
*/
#ifndef FIOCLEX
didcch = 1;
#endif
#endif /* notdef */
rechist();
(void) signal(SIGINT, parintr);
(void) signal(SIGQUIT, parintr);
(void) signal(SIGTERM, parterm); /* if doexec loses, screw */
lshift(kp->t_dcom, 1);
exiterr = 1;
doexec(kp);
/* NOTREACHED */
}
void
xechoit(t)
Char **t;
{
if (adrof(STRecho)) {
flush();
haderr = 1;
blkpr(t), xputchar('\n');
haderr = 0;
}
}
/*VARARGS0*/
void
dohash()
{
#ifdef COMMENT
struct stat stb;
#endif
DIR *dirp;
register struct dirent *dp;
register int cnt;
int i = 0;
struct varent *v = adrof(STRpath);
Char **pv;
int hshval;
tw_clear_comm_list();
havhash = 1;
for (cnt = 0; cnt < sizeof xhash; cnt++)
xhash[cnt] = 0;
if (v == 0)
return;
for (pv = v->vec; *pv; pv++, i++) {
if (pv[0][0] != '/')
continue;
dirp = opendir(short2str(*pv));
if (dirp == NULL)
continue;
#ifdef COMMENT /* this isn't needed. opendir won't open
* non-dirs */
if (fstat(dirp->dd_fd, &stb) < 0 || !S_ISDIR(stb.st_mode)) {
(void) closedir(dirp);
continue;
}
#endif
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;
hshval = hash(hashname(str2short(dp->d_name)), i);
bis(xhash, hshval);
/* tw_comm_name_add (dp->d_name); */
}
(void) closedir(dirp);
}
}
void
dounhash()
{
havhash = 0;
}
#ifdef VFORK
void
hashstat()
{
if (hits + misses)
xprintf("%d hits, %d misses, %d%%\n",
hits, misses, 100 * hits / (hits + misses));
}
#endif
/*
* Hash a command name.
*/
static int
hashname(cp)
register Char *cp;
{
register long h = 0;
while (*cp)
h = hash(h, *cp++);
return ((int) h);
}
int
iscommand(name)
Char *name;
{
register Char **pv;
register Char *sav;
register struct varent *v;
register bool slash = any(short2str(name), '/');
register int hshval = 0, hshval1, i;
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)
hshval = hashname(name);
i = 0;
do {
if (!slash && pv[0][0] == '/' && havhash) {
hshval1 = hash(hshval, i);
if (!bit(xhash, hshval1))
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...
*/
int
executable(dir, name, dir_ok)
Char *dir, *name;
bool dir_ok;
{
struct stat stbuf;
Char path[MAXPATHLEN + 1];
char *strname;
if (dir && *dir) {
copyn(path, dir, MAXPATHLEN);
catn(path, name, MAXPATHLEN);
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))));
}
void
tellmewhat(lex)
struct wordent *lex;
{
register int i;
register struct biltins *bptr;
register struct wordent *sp = lex->next;
bool aliased = 0;
Char *s0, *s1, *s2;
Char qc;
if (adrof1(sp->word, &aliases)) {
alias(lex);
sp = lex->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 (aliased)
prlex(lex);
xprintf("%s: shell built-in command.\n", short2str(sp->word));
flush();
sp->word = s0; /* we save and then restore this */
return;
}
}
if (i = iscommand(strip(sp->word))) {
register Char **pv;
register struct varent *v;
bool 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)) {
sp->word = Strspl(STRdt_l, sp->word);
prlex(lex);
xfree((ptr_t) sp->word);
sp->word = s0; /* we save and then restore this */
return;
}
s1 = Strspl(*pv, STRslash);
sp->word = Strspl(s1, sp->word);
xfree((ptr_t) s1);
prlex(lex);
xfree((ptr_t) sp->word);
}
else {
if (aliased)
prlex(lex);
xprintf("%s: Command not found.\n", short2str(sp->word));
flush();
}
sp->word = s0; /* we save and then restore this */
}