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freebsd/bin/sh/eval.c
Jilles Tjoelker 292e667663 sh: Do parameter expansion before printing PS4 (set -x). 
The function name expandstr() and the general idea of doing this kind of
expansion by treating the text as a here document without end marker is from
dash.

All variants of parameter expansion and arithmetic expansion also work (the
latter is not required by POSIX but it does not take extra code and many
other shells also allow it).

Command substitution is prevented because I think it causes too much code to
be re-entered (for example creating an unbounded recursion of trace lines).

Unfortunately, our LINENO is somewhat crude, otherwise PS4='$LINENO+ ' would
be quite useful.
2011-06-09 23:12:23 +00:00

1272 lines
28 KiB
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/*-
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Kenneth Almquist.
*
* 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.
* 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.
*/
#ifndef lint
#if 0
static char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95";
#endif
#endif /* not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <paths.h>
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/resource.h>
#include <sys/wait.h> /* For WIFSIGNALED(status) */
#include <errno.h>
/*
* Evaluate a command.
*/
#include "shell.h"
#include "nodes.h"
#include "syntax.h"
#include "expand.h"
#include "parser.h"
#include "jobs.h"
#include "eval.h"
#include "builtins.h"
#include "options.h"
#include "exec.h"
#include "redir.h"
#include "input.h"
#include "output.h"
#include "trap.h"
#include "var.h"
#include "memalloc.h"
#include "error.h"
#include "show.h"
#include "mystring.h"
#ifndef NO_HISTORY
#include "myhistedit.h"
#endif
int evalskip; /* set if we are skipping commands */
static int skipcount; /* number of levels to skip */
MKINIT int loopnest; /* current loop nesting level */
int funcnest; /* depth of function calls */
static int builtin_flags; /* evalcommand flags for builtins */
char *commandname;
struct strlist *cmdenviron;
int exitstatus; /* exit status of last command */
int oexitstatus; /* saved exit status */
static void evalloop(union node *, int);
static void evalfor(union node *, int);
static void evalcase(union node *, int);
static void evalsubshell(union node *, int);
static void evalredir(union node *, int);
static void expredir(union node *);
static void evalpipe(union node *);
static int is_valid_fast_cmdsubst(union node *n);
static void evalcommand(union node *, int, struct backcmd *);
static void prehash(union node *);
/*
* Called to reset things after an exception.
*/
#ifdef mkinit
INCLUDE "eval.h"
RESET {
evalskip = 0;
loopnest = 0;
funcnest = 0;
}
#endif
/*
* The eval command.
*/
int
evalcmd(int argc, char **argv)
{
char *p;
char *concat;
char **ap;
if (argc > 1) {
p = argv[1];
if (argc > 2) {
STARTSTACKSTR(concat);
ap = argv + 2;
for (;;) {
STPUTS(p, concat);
if ((p = *ap++) == NULL)
break;
STPUTC(' ', concat);
}
STPUTC('\0', concat);
p = grabstackstr(concat);
}
evalstring(p, builtin_flags & EV_TESTED);
} else
exitstatus = 0;
return exitstatus;
}
/*
* Execute a command or commands contained in a string.
*/
void
evalstring(char *s, int flags)
{
union node *n;
struct stackmark smark;
int flags_exit;
int any;
flags_exit = flags & EV_EXIT;
flags &= ~EV_EXIT;
any = 0;
setstackmark(&smark);
setinputstring(s, 1);
while ((n = parsecmd(0)) != NEOF) {
if (n != NULL && !nflag) {
if (flags_exit && preadateof())
evaltree(n, flags | EV_EXIT);
else
evaltree(n, flags);
any = 1;
}
popstackmark(&smark);
}
popfile();
popstackmark(&smark);
if (!any)
exitstatus = 0;
if (flags_exit)
exraise(EXEXIT);
}
/*
* Evaluate a parse tree. The value is left in the global variable
* exitstatus.
*/
void
evaltree(union node *n, int flags)
{
int do_etest;
union node *next;
do_etest = 0;
if (n == NULL) {
TRACE(("evaltree(NULL) called\n"));
exitstatus = 0;
goto out;
}
do {
next = NULL;
#ifndef NO_HISTORY
displayhist = 1; /* show history substitutions done with fc */
#endif
TRACE(("evaltree(%p: %d) called\n", (void *)n, n->type));
switch (n->type) {
case NSEMI:
evaltree(n->nbinary.ch1, flags & ~EV_EXIT);
if (evalskip)
goto out;
next = n->nbinary.ch2;
break;
case NAND:
evaltree(n->nbinary.ch1, EV_TESTED);
if (evalskip || exitstatus != 0) {
goto out;
}
next = n->nbinary.ch2;
break;
case NOR:
evaltree(n->nbinary.ch1, EV_TESTED);
if (evalskip || exitstatus == 0)
goto out;
next = n->nbinary.ch2;
break;
case NREDIR:
evalredir(n, flags);
break;
case NSUBSHELL:
evalsubshell(n, flags);
do_etest = !(flags & EV_TESTED);
break;
case NBACKGND:
evalsubshell(n, flags);
break;
case NIF: {
evaltree(n->nif.test, EV_TESTED);
if (evalskip)
goto out;
if (exitstatus == 0)
next = n->nif.ifpart;
else if (n->nif.elsepart)
next = n->nif.elsepart;
else
exitstatus = 0;
break;
}
case NWHILE:
case NUNTIL:
evalloop(n, flags & ~EV_EXIT);
break;
case NFOR:
evalfor(n, flags & ~EV_EXIT);
break;
case NCASE:
evalcase(n, flags);
break;
case NDEFUN:
defun(n->narg.text, n->narg.next);
exitstatus = 0;
break;
case NNOT:
evaltree(n->nnot.com, EV_TESTED);
exitstatus = !exitstatus;
break;
case NPIPE:
evalpipe(n);
do_etest = !(flags & EV_TESTED);
break;
case NCMD:
evalcommand(n, flags, (struct backcmd *)NULL);
do_etest = !(flags & EV_TESTED);
break;
default:
out1fmt("Node type = %d\n", n->type);
flushout(&output);
break;
}
n = next;
} while (n != NULL);
out:
if (pendingsigs)
dotrap();
if (eflag && exitstatus != 0 && do_etest)
exitshell(exitstatus);
if (flags & EV_EXIT)
exraise(EXEXIT);
}
static void
evalloop(union node *n, int flags)
{
int status;
loopnest++;
status = 0;
for (;;) {
evaltree(n->nbinary.ch1, EV_TESTED);
if (evalskip) {
skipping: if (evalskip == SKIPCONT && --skipcount <= 0) {
evalskip = 0;
continue;
}
if (evalskip == SKIPBREAK && --skipcount <= 0)
evalskip = 0;
if (evalskip == SKIPFUNC || evalskip == SKIPFILE)
status = exitstatus;
break;
}
if (n->type == NWHILE) {
if (exitstatus != 0)
break;
} else {
if (exitstatus == 0)
break;
}
evaltree(n->nbinary.ch2, flags);
status = exitstatus;
if (evalskip)
goto skipping;
}
loopnest--;
exitstatus = status;
}
static void
evalfor(union node *n, int flags)
{
struct arglist arglist;
union node *argp;
struct strlist *sp;
struct stackmark smark;
setstackmark(&smark);
arglist.lastp = &arglist.list;
for (argp = n->nfor.args ; argp ; argp = argp->narg.next) {
oexitstatus = exitstatus;
expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
if (evalskip)
goto out;
}
*arglist.lastp = NULL;
exitstatus = 0;
loopnest++;
for (sp = arglist.list ; sp ; sp = sp->next) {
setvar(n->nfor.var, sp->text, 0);
evaltree(n->nfor.body, flags);
if (evalskip) {
if (evalskip == SKIPCONT && --skipcount <= 0) {
evalskip = 0;
continue;
}
if (evalskip == SKIPBREAK && --skipcount <= 0)
evalskip = 0;
break;
}
}
loopnest--;
out:
popstackmark(&smark);
}
static void
evalcase(union node *n, int flags)
{
union node *cp;
union node *patp;
struct arglist arglist;
struct stackmark smark;
setstackmark(&smark);
arglist.lastp = &arglist.list;
oexitstatus = exitstatus;
exitstatus = 0;
expandarg(n->ncase.expr, &arglist, EXP_TILDE);
for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) {
for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) {
if (casematch(patp, arglist.list->text)) {
if (evalskip == 0) {
evaltree(cp->nclist.body, flags);
}
goto out;
}
}
}
out:
popstackmark(&smark);
}
/*
* Kick off a subshell to evaluate a tree.
*/
static void
evalsubshell(union node *n, int flags)
{
struct job *jp;
int backgnd = (n->type == NBACKGND);
oexitstatus = exitstatus;
expredir(n->nredir.redirect);
if ((!backgnd && flags & EV_EXIT && !have_traps()) ||
forkshell(jp = makejob(n, 1), n, backgnd) == 0) {
if (backgnd)
flags &=~ EV_TESTED;
redirect(n->nredir.redirect, 0);
evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */
} else if (! backgnd) {
INTOFF;
exitstatus = waitforjob(jp, (int *)NULL);
INTON;
} else
exitstatus = 0;
}
/*
* Evaluate a redirected compound command.
*/
static void
evalredir(union node *n, int flags)
{
struct jmploc jmploc;
struct jmploc *savehandler;
volatile int in_redirect = 1;
oexitstatus = exitstatus;
expredir(n->nredir.redirect);
savehandler = handler;
if (setjmp(jmploc.loc)) {
int e;
handler = savehandler;
e = exception;
popredir();
if (e == EXERROR || e == EXEXEC) {
if (in_redirect) {
exitstatus = 2;
return;
}
}
longjmp(handler->loc, 1);
} else {
INTOFF;
handler = &jmploc;
redirect(n->nredir.redirect, REDIR_PUSH);
in_redirect = 0;
INTON;
evaltree(n->nredir.n, flags);
}
INTOFF;
handler = savehandler;
popredir();
INTON;
}
/*
* Compute the names of the files in a redirection list.
*/
static void
expredir(union node *n)
{
union node *redir;
for (redir = n ; redir ; redir = redir->nfile.next) {
struct arglist fn;
fn.lastp = &fn.list;
switch (redir->type) {
case NFROM:
case NTO:
case NFROMTO:
case NAPPEND:
case NCLOBBER:
expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR);
redir->nfile.expfname = fn.list->text;
break;
case NFROMFD:
case NTOFD:
if (redir->ndup.vname) {
expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR);
fixredir(redir, fn.list->text, 1);
}
break;
}
}
}
/*
* Evaluate a pipeline. All the processes in the pipeline are children
* of the process creating the pipeline. (This differs from some versions
* of the shell, which make the last process in a pipeline the parent
* of all the rest.)
*/
static void
evalpipe(union node *n)
{
struct job *jp;
struct nodelist *lp;
int pipelen;
int prevfd;
int pip[2];
TRACE(("evalpipe(%p) called\n", (void *)n));
pipelen = 0;
for (lp = n->npipe.cmdlist ; lp ; lp = lp->next)
pipelen++;
INTOFF;
jp = makejob(n, pipelen);
prevfd = -1;
for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
prehash(lp->n);
pip[1] = -1;
if (lp->next) {
if (pipe(pip) < 0) {
close(prevfd);
error("Pipe call failed: %s", strerror(errno));
}
}
if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) {
INTON;
if (prevfd > 0) {
dup2(prevfd, 0);
close(prevfd);
}
if (pip[1] >= 0) {
if (!(prevfd >= 0 && pip[0] == 0))
close(pip[0]);
if (pip[1] != 1) {
dup2(pip[1], 1);
close(pip[1]);
}
}
evaltree(lp->n, EV_EXIT);
}
if (prevfd >= 0)
close(prevfd);
prevfd = pip[0];
if (pip[1] != -1)
close(pip[1]);
}
INTON;
if (n->npipe.backgnd == 0) {
INTOFF;
exitstatus = waitforjob(jp, (int *)NULL);
TRACE(("evalpipe: job done exit status %d\n", exitstatus));
INTON;
} else
exitstatus = 0;
}
static int
is_valid_fast_cmdsubst(union node *n)
{
union node *argp;
if (n->type != NCMD)
return 0;
for (argp = n->ncmd.args ; argp ; argp = argp->narg.next)
if (expandhassideeffects(argp->narg.text))
return 0;
return 1;
}
/*
* Execute a command inside back quotes. If it's a builtin command, we
* want to save its output in a block obtained from malloc. Otherwise
* we fork off a subprocess and get the output of the command via a pipe.
* Should be called with interrupts off.
*/
void
evalbackcmd(union node *n, struct backcmd *result)
{
int pip[2];
struct job *jp;
struct stackmark smark; /* unnecessary */
struct jmploc jmploc;
struct jmploc *savehandler;
setstackmark(&smark);
result->fd = -1;
result->buf = NULL;
result->nleft = 0;
result->jp = NULL;
if (n == NULL) {
exitstatus = 0;
goto out;
}
if (is_valid_fast_cmdsubst(n)) {
exitstatus = oexitstatus;
savehandler = handler;
if (setjmp(jmploc.loc)) {
if (exception == EXERROR || exception == EXEXEC)
exitstatus = 2;
else if (exception != 0) {
handler = savehandler;
longjmp(handler->loc, 1);
}
} else {
handler = &jmploc;
evalcommand(n, EV_BACKCMD, result);
}
handler = savehandler;
} else {
exitstatus = 0;
if (pipe(pip) < 0)
error("Pipe call failed: %s", strerror(errno));
jp = makejob(n, 1);
if (forkshell(jp, n, FORK_NOJOB) == 0) {
FORCEINTON;
close(pip[0]);
if (pip[1] != 1) {
dup2(pip[1], 1);
close(pip[1]);
}
evaltree(n, EV_EXIT);
}
close(pip[1]);
result->fd = pip[0];
result->jp = jp;
}
out:
popstackmark(&smark);
TRACE(("evalbackcmd done: fd=%d buf=%p nleft=%d jp=%p\n",
result->fd, result->buf, result->nleft, result->jp));
}
/*
* Check if a builtin can safely be executed in the same process,
* even though it should be in a subshell (command substitution).
* Note that jobid, jobs, times and trap can show information not
* available in a child process; this is deliberate.
* The arguments should already have been expanded.
*/
static int
safe_builtin(int idx, int argc, char **argv)
{
if (idx == BLTINCMD || idx == COMMANDCMD || idx == ECHOCMD ||
idx == FALSECMD || idx == JOBIDCMD || idx == JOBSCMD ||
idx == KILLCMD || idx == PRINTFCMD || idx == PWDCMD ||
idx == TESTCMD || idx == TIMESCMD || idx == TRUECMD ||
idx == TYPECMD)
return (1);
if (idx == EXPORTCMD || idx == TRAPCMD || idx == ULIMITCMD ||
idx == UMASKCMD)
return (argc <= 1 || (argc == 2 && argv[1][0] == '-'));
if (idx == SETCMD)
return (argc <= 1 || (argc == 2 && (argv[1][0] == '-' ||
argv[1][0] == '+') && argv[1][1] == 'o' &&
argv[1][2] == '\0'));
return (0);
}
/*
* Execute a simple command.
* Note: This may or may not return if (flags & EV_EXIT).
*/
static void
evalcommand(union node *cmd, int flags, struct backcmd *backcmd)
{
struct stackmark smark;
union node *argp;
struct arglist arglist;
struct arglist varlist;
char **argv;
int argc;
char **envp;
int varflag;
struct strlist *sp;
int mode;
int pip[2];
struct cmdentry cmdentry;
struct job *jp;
struct jmploc jmploc;
struct jmploc *savehandler;
char *savecmdname;
struct shparam saveparam;
struct localvar *savelocalvars;
struct parsefile *savetopfile;
volatile int e;
char *lastarg;
int realstatus;
int do_clearcmdentry;
const char *path = pathval();
/* First expand the arguments. */
TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags));
setstackmark(&smark);
arglist.lastp = &arglist.list;
varlist.lastp = &varlist.list;
varflag = 1;
jp = NULL;
do_clearcmdentry = 0;
oexitstatus = exitstatus;
exitstatus = 0;
for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
if (varflag && isassignment(argp->narg.text)) {
expandarg(argp, &varlist, EXP_VARTILDE);
continue;
}
expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
varflag = 0;
}
*arglist.lastp = NULL;
*varlist.lastp = NULL;
expredir(cmd->ncmd.redirect);
argc = 0;
for (sp = arglist.list ; sp ; sp = sp->next)
argc++;
/* Add one slot at the beginning for tryexec(). */
argv = stalloc(sizeof (char *) * (argc + 2));
argv++;
for (sp = arglist.list ; sp ; sp = sp->next) {
TRACE(("evalcommand arg: %s\n", sp->text));
*argv++ = sp->text;
}
*argv = NULL;
lastarg = NULL;
if (iflag && funcnest == 0 && argc > 0)
lastarg = argv[-1];
argv -= argc;
/* Print the command if xflag is set. */
if (xflag) {
char sep = 0;
const char *p, *ps4;
ps4 = expandstr(ps4val());
out2str(ps4 != NULL ? ps4 : ps4val());
for (sp = varlist.list ; sp ; sp = sp->next) {
if (sep != 0)
out2c(' ');
p = strchr(sp->text, '=');
if (p != NULL) {
p++;
outbin(sp->text, p - sp->text, out2);
out2qstr(p);
} else
out2qstr(sp->text);
sep = ' ';
}
for (sp = arglist.list ; sp ; sp = sp->next) {
if (sep != 0)
out2c(' ');
/* Disambiguate command looking like assignment. */
if (sp == arglist.list &&
strchr(sp->text, '=') != NULL &&
strchr(sp->text, '\'') == NULL) {
out2c('\'');
out2str(sp->text);
out2c('\'');
} else
out2qstr(sp->text);
sep = ' ';
}
out2c('\n');
flushout(&errout);
}
/* Now locate the command. */
if (argc == 0) {
/* Variable assignment(s) without command */
cmdentry.cmdtype = CMDBUILTIN;
cmdentry.u.index = BLTINCMD;
cmdentry.special = 0;
} else {
static const char PATH[] = "PATH=";
int cmd_flags = 0, bltinonly = 0;
/*
* Modify the command lookup path, if a PATH= assignment
* is present
*/
for (sp = varlist.list ; sp ; sp = sp->next)
if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) {
path = sp->text + sizeof(PATH) - 1;
/*
* On `PATH=... command`, we need to make
* sure that the command isn't using the
* non-updated hash table of the outer PATH
* setting and we need to make sure that
* the hash table isn't filled with items
* from the temporary setting.
*
* It would be better to forbit using and
* updating the table while this command
* runs, by the command finding mechanism
* is heavily integrated with hash handling,
* so we just delete the hash before and after
* the command runs. Partly deleting like
* changepatch() does doesn't seem worth the
* bookinging effort, since most such runs add
* directories in front of the new PATH.
*/
clearcmdentry();
do_clearcmdentry = 1;
}
for (;;) {
if (bltinonly) {
cmdentry.u.index = find_builtin(*argv, &cmdentry.special);
if (cmdentry.u.index < 0) {
cmdentry.u.index = BLTINCMD;
argv--;
argc++;
break;
}
} else
find_command(argv[0], &cmdentry, cmd_flags, path);
/* implement the bltin and command builtins here */
if (cmdentry.cmdtype != CMDBUILTIN)
break;
if (cmdentry.u.index == BLTINCMD) {
if (argc == 1)
break;
argv++;
argc--;
bltinonly = 1;
} else if (cmdentry.u.index == COMMANDCMD) {
if (argc == 1)
break;
if (!strcmp(argv[1], "-p")) {
if (argc == 2)
break;
if (argv[2][0] == '-') {
if (strcmp(argv[2], "--"))
break;
if (argc == 3)
break;
argv += 3;
argc -= 3;
} else {
argv += 2;
argc -= 2;
}
path = _PATH_STDPATH;
clearcmdentry();
do_clearcmdentry = 1;
} else if (!strcmp(argv[1], "--")) {
if (argc == 2)
break;
argv += 2;
argc -= 2;
} else if (argv[1][0] == '-')
break;
else {
argv++;
argc--;
}
cmd_flags |= DO_NOFUNC;
bltinonly = 0;
} else
break;
}
/*
* Special builtins lose their special properties when
* called via 'command'.
*/
if (cmd_flags & DO_NOFUNC)
cmdentry.special = 0;
}
/* Fork off a child process if necessary. */
if (cmd->ncmd.backgnd
|| ((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN)
&& ((flags & EV_EXIT) == 0 || have_traps()))
|| ((flags & EV_BACKCMD) != 0
&& (cmdentry.cmdtype != CMDBUILTIN ||
!safe_builtin(cmdentry.u.index, argc, argv)))) {
jp = makejob(cmd, 1);
mode = cmd->ncmd.backgnd;
if (flags & EV_BACKCMD) {
mode = FORK_NOJOB;
if (pipe(pip) < 0)
error("Pipe call failed: %s", strerror(errno));
}
if (forkshell(jp, cmd, mode) != 0)
goto parent; /* at end of routine */
if (flags & EV_BACKCMD) {
FORCEINTON;
close(pip[0]);
if (pip[1] != 1) {
dup2(pip[1], 1);
close(pip[1]);
}
}
flags |= EV_EXIT;
}
/* This is the child process if a fork occurred. */
/* Execute the command. */
if (cmdentry.cmdtype == CMDFUNCTION) {
#ifdef DEBUG
trputs("Shell function: "); trargs(argv);
#endif
saveparam = shellparam;
shellparam.malloc = 0;
shellparam.reset = 1;
shellparam.nparam = argc - 1;
shellparam.p = argv + 1;
shellparam.optnext = NULL;
INTOFF;
savelocalvars = localvars;
localvars = NULL;
reffunc(cmdentry.u.func);
savehandler = handler;
if (setjmp(jmploc.loc)) {
freeparam(&shellparam);
shellparam = saveparam;
popredir();
unreffunc(cmdentry.u.func);
poplocalvars();
localvars = savelocalvars;
funcnest--;
handler = savehandler;
longjmp(handler->loc, 1);
}
handler = &jmploc;
funcnest++;
redirect(cmd->ncmd.redirect, REDIR_PUSH);
INTON;
for (sp = varlist.list ; sp ; sp = sp->next)
mklocal(sp->text);
exitstatus = oexitstatus;
evaltree(getfuncnode(cmdentry.u.func),
flags & (EV_TESTED | EV_EXIT));
INTOFF;
unreffunc(cmdentry.u.func);
poplocalvars();
localvars = savelocalvars;
freeparam(&shellparam);
shellparam = saveparam;
handler = savehandler;
funcnest--;
popredir();
INTON;
if (evalskip == SKIPFUNC) {
evalskip = 0;
skipcount = 0;
}
if (jp)
exitshell(exitstatus);
} else if (cmdentry.cmdtype == CMDBUILTIN) {
#ifdef DEBUG
trputs("builtin command: "); trargs(argv);
#endif
mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH;
if (flags == EV_BACKCMD) {
memout.nleft = 0;
memout.nextc = memout.buf;
memout.bufsize = 64;
mode |= REDIR_BACKQ;
cmdentry.special = 0;
}
savecmdname = commandname;
savetopfile = getcurrentfile();
cmdenviron = varlist.list;
e = -1;
savehandler = handler;
if (setjmp(jmploc.loc)) {
e = exception;
if (e == EXINT)
exitstatus = SIGINT+128;
else if (e != EXEXIT)
exitstatus = 2;
goto cmddone;
}
handler = &jmploc;
redirect(cmd->ncmd.redirect, mode);
/*
* If there is no command word, redirection errors should
* not be fatal but assignment errors should.
*/
if (argc == 0 && !(flags & EV_BACKCMD))
cmdentry.special = 1;
listsetvar(cmdenviron, cmdentry.special ? 0 : VNOSET);
if (argc > 0)
bltinsetlocale();
commandname = argv[0];
argptr = argv + 1;
nextopt_optptr = NULL; /* initialize nextopt */
builtin_flags = flags;
exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv);
flushall();
cmddone:
if (argc > 0)
bltinunsetlocale();
cmdenviron = NULL;
out1 = &output;
out2 = &errout;
freestdout();
handler = savehandler;
commandname = savecmdname;
if (jp)
exitshell(exitstatus);
if (flags == EV_BACKCMD) {
backcmd->buf = memout.buf;
backcmd->nleft = memout.nextc - memout.buf;
memout.buf = NULL;
}
if (cmdentry.u.index != EXECCMD)
popredir();
if (e != -1) {
if ((e != EXERROR && e != EXEXEC)
|| cmdentry.special)
exraise(e);
popfilesupto(savetopfile);
if (flags != EV_BACKCMD)
FORCEINTON;
}
} else {
#ifdef DEBUG
trputs("normal command: "); trargs(argv);
#endif
redirect(cmd->ncmd.redirect, 0);
for (sp = varlist.list ; sp ; sp = sp->next)
setvareq(sp->text, VEXPORT|VSTACK);
envp = environment();
shellexec(argv, envp, path, cmdentry.u.index);
/*NOTREACHED*/
}
goto out;
parent: /* parent process gets here (if we forked) */
if (mode == FORK_FG) { /* argument to fork */
INTOFF;
exitstatus = waitforjob(jp, &realstatus);
INTON;
if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) {
evalskip = SKIPBREAK;
skipcount = loopnest;
}
} else if (mode == FORK_NOJOB) {
backcmd->fd = pip[0];
close(pip[1]);
backcmd->jp = jp;
} else
exitstatus = 0;
out:
if (lastarg)
setvar("_", lastarg, 0);
if (do_clearcmdentry)
clearcmdentry();
popstackmark(&smark);
}
/*
* Search for a command. This is called before we fork so that the
* location of the command will be available in the parent as well as
* the child. The check for "goodname" is an overly conservative
* check that the name will not be subject to expansion.
*/
static void
prehash(union node *n)
{
struct cmdentry entry;
if (n && n->type == NCMD && n->ncmd.args)
if (goodname(n->ncmd.args->narg.text))
find_command(n->ncmd.args->narg.text, &entry, 0,
pathval());
}
/*
* Builtin commands. Builtin commands whose functions are closely
* tied to evaluation are implemented here.
*/
/*
* No command given, a bltin command with no arguments, or a bltin command
* with an invalid name.
*/
int
bltincmd(int argc, char **argv)
{
if (argc > 1) {
out2fmt_flush("%s: not found\n", argv[1]);
return 127;
}
/*
* Preserve exitstatus of a previous possible redirection
* as POSIX mandates
*/
return exitstatus;
}
/*
* Handle break and continue commands. Break, continue, and return are
* all handled by setting the evalskip flag. The evaluation routines
* above all check this flag, and if it is set they start skipping
* commands rather than executing them. The variable skipcount is
* the number of loops to break/continue, or the number of function
* levels to return. (The latter is always 1.) It should probably
* be an error to break out of more loops than exist, but it isn't
* in the standard shell so we don't make it one here.
*/
int
breakcmd(int argc, char **argv)
{
int n = argc > 1 ? number(argv[1]) : 1;
if (n > loopnest)
n = loopnest;
if (n > 0) {
evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK;
skipcount = n;
}
return 0;
}
/*
* The `command' command.
*/
int
commandcmd(int argc, char **argv)
{
const char *path;
int ch;
int cmd = -1;
path = bltinlookup("PATH", 1);
optind = optreset = 1;
opterr = 0;
while ((ch = getopt(argc, argv, "pvV")) != -1) {
switch (ch) {
case 'p':
path = _PATH_STDPATH;
break;
case 'v':
cmd = TYPECMD_SMALLV;
break;
case 'V':
cmd = TYPECMD_BIGV;
break;
case '?':
default:
error("unknown option: -%c", optopt);
}
}
argc -= optind;
argv += optind;
if (cmd != -1) {
if (argc != 1)
error("wrong number of arguments");
return typecmd_impl(2, argv - 1, cmd, path);
}
if (argc != 0)
error("commandcmd bad call");
/*
* Do nothing successfully if no command was specified;
* ksh also does this.
*/
return 0;
}
/*
* The return command.
*/
int
returncmd(int argc, char **argv)
{
int ret = argc > 1 ? number(argv[1]) : oexitstatus;
if (funcnest) {
evalskip = SKIPFUNC;
skipcount = 1;
} else {
/* skip the rest of the file */
evalskip = SKIPFILE;
skipcount = 1;
}
return ret;
}
int
falsecmd(int argc __unused, char **argv __unused)
{
return 1;
}
int
truecmd(int argc __unused, char **argv __unused)
{
return 0;
}
int
execcmd(int argc, char **argv)
{
/*
* Because we have historically not supported any options,
* only treat "--" specially.
*/
if (argc > 1 && strcmp(argv[1], "--") == 0)
argc--, argv++;
if (argc > 1) {
struct strlist *sp;
iflag = 0; /* exit on error */
mflag = 0;
optschanged();
for (sp = cmdenviron; sp ; sp = sp->next)
setvareq(sp->text, VEXPORT|VSTACK);
shellexec(argv + 1, environment(), pathval(), 0);
}
return 0;
}
int
timescmd(int argc __unused, char **argv __unused)
{
struct rusage ru;
long shumins, shsmins, chumins, chsmins;
double shusecs, shssecs, chusecs, chssecs;
if (getrusage(RUSAGE_SELF, &ru) < 0)
return 1;
shumins = ru.ru_utime.tv_sec / 60;
shusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.;
shsmins = ru.ru_stime.tv_sec / 60;
shssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.;
if (getrusage(RUSAGE_CHILDREN, &ru) < 0)
return 1;
chumins = ru.ru_utime.tv_sec / 60;
chusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.;
chsmins = ru.ru_stime.tv_sec / 60;
chssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.;
out1fmt("%ldm%.3fs %ldm%.3fs\n%ldm%.3fs %ldm%.3fs\n", shumins,
shusecs, shsmins, shssecs, chumins, chusecs, chsmins, chssecs);
return 0;
}
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