eval.c revision 53891
11556Srgrimes/*- 21556Srgrimes * Copyright (c) 1993 31556Srgrimes * The Regents of the University of California. All rights reserved. 41556Srgrimes * 51556Srgrimes * This code is derived from software contributed to Berkeley by 61556Srgrimes * Kenneth Almquist. 71556Srgrimes * 81556Srgrimes * Redistribution and use in source and binary forms, with or without 91556Srgrimes * modification, are permitted provided that the following conditions 101556Srgrimes * are met: 111556Srgrimes * 1. Redistributions of source code must retain the above copyright 121556Srgrimes * notice, this list of conditions and the following disclaimer. 131556Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 141556Srgrimes * notice, this list of conditions and the following disclaimer in the 151556Srgrimes * documentation and/or other materials provided with the distribution. 161556Srgrimes * 3. All advertising materials mentioning features or use of this software 171556Srgrimes * must display the following acknowledgement: 181556Srgrimes * This product includes software developed by the University of 191556Srgrimes * California, Berkeley and its contributors. 201556Srgrimes * 4. Neither the name of the University nor the names of its contributors 211556Srgrimes * may be used to endorse or promote products derived from this software 221556Srgrimes * without specific prior written permission. 231556Srgrimes * 241556Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 251556Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 261556Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 271556Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 281556Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 291556Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 301556Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 311556Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 321556Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 331556Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 341556Srgrimes * SUCH DAMAGE. 351556Srgrimes */ 361556Srgrimes 371556Srgrimes#ifndef lint 3836150Scharnier#if 0 3936150Scharnierstatic char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95"; 4036150Scharnier#endif 4136150Scharnierstatic const char rcsid[] = 4250471Speter "$FreeBSD: head/bin/sh/eval.c 53891 1999-11-29 19:11:01Z cracauer $"; 431556Srgrimes#endif /* not lint */ 441556Srgrimes 4517987Speter#include <signal.h> 4617987Speter#include <unistd.h> 4745266Scracauer#include <sys/wait.h> /* For WIFSIGNALED(status) */ 4853891Scracauer#include <errno.h> 4917987Speter 501556Srgrimes/* 511556Srgrimes * Evaluate a command. 521556Srgrimes */ 531556Srgrimes 541556Srgrimes#include "shell.h" 551556Srgrimes#include "nodes.h" 561556Srgrimes#include "syntax.h" 571556Srgrimes#include "expand.h" 581556Srgrimes#include "parser.h" 591556Srgrimes#include "jobs.h" 601556Srgrimes#include "eval.h" 611556Srgrimes#include "builtins.h" 621556Srgrimes#include "options.h" 631556Srgrimes#include "exec.h" 641556Srgrimes#include "redir.h" 651556Srgrimes#include "input.h" 661556Srgrimes#include "output.h" 671556Srgrimes#include "trap.h" 681556Srgrimes#include "var.h" 691556Srgrimes#include "memalloc.h" 701556Srgrimes#include "error.h" 7117987Speter#include "show.h" 721556Srgrimes#include "mystring.h" 7317987Speter#ifndef NO_HISTORY 741556Srgrimes#include "myhistedit.h" 7517987Speter#endif 761556Srgrimes 771556Srgrimes 781556Srgrimes/* flags in argument to evaltree */ 791556Srgrimes#define EV_EXIT 01 /* exit after evaluating tree */ 801556Srgrimes#define EV_TESTED 02 /* exit status is checked; ignore -e flag */ 811556Srgrimes#define EV_BACKCMD 04 /* command executing within back quotes */ 821556Srgrimes 831556SrgrimesMKINIT int evalskip; /* set if we are skipping commands */ 841556SrgrimesSTATIC int skipcount; /* number of levels to skip */ 851556SrgrimesMKINIT int loopnest; /* current loop nesting level */ 861556Srgrimesint funcnest; /* depth of function calls */ 871556Srgrimes 881556Srgrimes 891556Srgrimeschar *commandname; 901556Srgrimesstruct strlist *cmdenviron; 911556Srgrimesint exitstatus; /* exit status of last command */ 9217987Speterint oexitstatus; /* saved exit status */ 931556Srgrimes 941556Srgrimes 9517987SpeterSTATIC void evalloop __P((union node *)); 9617987SpeterSTATIC void evalfor __P((union node *)); 9717987SpeterSTATIC void evalcase __P((union node *, int)); 9817987SpeterSTATIC void evalsubshell __P((union node *, int)); 9917987SpeterSTATIC void expredir __P((union node *)); 10017987SpeterSTATIC void evalpipe __P((union node *)); 10117987SpeterSTATIC void evalcommand __P((union node *, int, struct backcmd *)); 10217987SpeterSTATIC void prehash __P((union node *)); 1031556Srgrimes 1041556Srgrimes 1051556Srgrimes/* 1061556Srgrimes * Called to reset things after an exception. 1071556Srgrimes */ 1081556Srgrimes 1091556Srgrimes#ifdef mkinit 1101556SrgrimesINCLUDE "eval.h" 1111556Srgrimes 1121556SrgrimesRESET { 1131556Srgrimes evalskip = 0; 1141556Srgrimes loopnest = 0; 1151556Srgrimes funcnest = 0; 1161556Srgrimes} 1171556Srgrimes 1181556SrgrimesSHELLPROC { 1191556Srgrimes exitstatus = 0; 1201556Srgrimes} 1211556Srgrimes#endif 1221556Srgrimes 1231556Srgrimes 1241556Srgrimes 1251556Srgrimes/* 12646684Skris * The eval command. 1271556Srgrimes */ 1281556Srgrimes 12917987Speterint 13020425Ssteveevalcmd(argc, argv) 13117987Speter int argc; 13220425Ssteve char **argv; 1331556Srgrimes{ 1341556Srgrimes char *p; 1351556Srgrimes char *concat; 1361556Srgrimes char **ap; 1371556Srgrimes 1381556Srgrimes if (argc > 1) { 1391556Srgrimes p = argv[1]; 1401556Srgrimes if (argc > 2) { 1411556Srgrimes STARTSTACKSTR(concat); 1421556Srgrimes ap = argv + 2; 1431556Srgrimes for (;;) { 1441556Srgrimes while (*p) 1451556Srgrimes STPUTC(*p++, concat); 1461556Srgrimes if ((p = *ap++) == NULL) 1471556Srgrimes break; 1481556Srgrimes STPUTC(' ', concat); 1491556Srgrimes } 1501556Srgrimes STPUTC('\0', concat); 1511556Srgrimes p = grabstackstr(concat); 1521556Srgrimes } 1531556Srgrimes evalstring(p); 1541556Srgrimes } 1551556Srgrimes return exitstatus; 1561556Srgrimes} 1571556Srgrimes 1581556Srgrimes 1591556Srgrimes/* 1601556Srgrimes * Execute a command or commands contained in a string. 1611556Srgrimes */ 1621556Srgrimes 1631556Srgrimesvoid 1641556Srgrimesevalstring(s) 1651556Srgrimes char *s; 1661556Srgrimes { 1671556Srgrimes union node *n; 1681556Srgrimes struct stackmark smark; 1691556Srgrimes 1701556Srgrimes setstackmark(&smark); 1711556Srgrimes setinputstring(s, 1); 1721556Srgrimes while ((n = parsecmd(0)) != NEOF) { 1731556Srgrimes evaltree(n, 0); 1741556Srgrimes popstackmark(&smark); 1751556Srgrimes } 1761556Srgrimes popfile(); 1771556Srgrimes popstackmark(&smark); 1781556Srgrimes} 1791556Srgrimes 1801556Srgrimes 1811556Srgrimes 1821556Srgrimes/* 1831556Srgrimes * Evaluate a parse tree. The value is left in the global variable 1841556Srgrimes * exitstatus. 1851556Srgrimes */ 1861556Srgrimes 1871556Srgrimesvoid 1881556Srgrimesevaltree(n, flags) 1891556Srgrimes union node *n; 19017987Speter int flags; 19117987Speter{ 1921556Srgrimes if (n == NULL) { 1931556Srgrimes TRACE(("evaltree(NULL) called\n")); 1941556Srgrimes exitstatus = 0; 1951556Srgrimes goto out; 1961556Srgrimes } 19717987Speter#ifndef NO_HISTORY 1981556Srgrimes displayhist = 1; /* show history substitutions done with fc */ 19917987Speter#endif 20017987Speter TRACE(("evaltree(0x%lx: %d) called\n", (long)n, n->type)); 2011556Srgrimes switch (n->type) { 2021556Srgrimes case NSEMI: 2031556Srgrimes evaltree(n->nbinary.ch1, 0); 2041556Srgrimes if (evalskip) 2051556Srgrimes goto out; 2061556Srgrimes evaltree(n->nbinary.ch2, flags); 2071556Srgrimes break; 2081556Srgrimes case NAND: 2091556Srgrimes evaltree(n->nbinary.ch1, EV_TESTED); 21018754Ssteve if (evalskip || exitstatus != 0) { 21118754Ssteve flags |= EV_TESTED; 2121556Srgrimes goto out; 21318754Ssteve } 2141556Srgrimes evaltree(n->nbinary.ch2, flags); 2151556Srgrimes break; 2161556Srgrimes case NOR: 2171556Srgrimes evaltree(n->nbinary.ch1, EV_TESTED); 2181556Srgrimes if (evalskip || exitstatus == 0) 2191556Srgrimes goto out; 2201556Srgrimes evaltree(n->nbinary.ch2, flags); 2211556Srgrimes break; 2221556Srgrimes case NREDIR: 2231556Srgrimes expredir(n->nredir.redirect); 2241556Srgrimes redirect(n->nredir.redirect, REDIR_PUSH); 2251556Srgrimes evaltree(n->nredir.n, flags); 2261556Srgrimes popredir(); 2271556Srgrimes break; 2281556Srgrimes case NSUBSHELL: 2291556Srgrimes evalsubshell(n, flags); 2301556Srgrimes break; 2311556Srgrimes case NBACKGND: 2321556Srgrimes evalsubshell(n, flags); 2331556Srgrimes break; 2341556Srgrimes case NIF: { 2351556Srgrimes evaltree(n->nif.test, EV_TESTED); 2361556Srgrimes if (evalskip) 2371556Srgrimes goto out; 23820425Ssteve if (exitstatus == 0) 2391556Srgrimes evaltree(n->nif.ifpart, flags); 24017987Speter else if (n->nif.elsepart) 2411556Srgrimes evaltree(n->nif.elsepart, flags); 24220425Ssteve else 24320425Ssteve exitstatus = 0; 2441556Srgrimes break; 2451556Srgrimes } 2461556Srgrimes case NWHILE: 2471556Srgrimes case NUNTIL: 2481556Srgrimes evalloop(n); 2491556Srgrimes break; 2501556Srgrimes case NFOR: 2511556Srgrimes evalfor(n); 2521556Srgrimes break; 2531556Srgrimes case NCASE: 2541556Srgrimes evalcase(n, flags); 2551556Srgrimes break; 2561556Srgrimes case NDEFUN: 2571556Srgrimes defun(n->narg.text, n->narg.next); 2581556Srgrimes exitstatus = 0; 2591556Srgrimes break; 2601556Srgrimes case NNOT: 2611556Srgrimes evaltree(n->nnot.com, EV_TESTED); 2621556Srgrimes exitstatus = !exitstatus; 2631556Srgrimes break; 2641556Srgrimes 2651556Srgrimes case NPIPE: 2661556Srgrimes evalpipe(n); 2671556Srgrimes break; 2681556Srgrimes case NCMD: 2691556Srgrimes evalcommand(n, flags, (struct backcmd *)NULL); 2701556Srgrimes break; 2711556Srgrimes default: 2721556Srgrimes out1fmt("Node type = %d\n", n->type); 2731556Srgrimes flushout(&output); 2741556Srgrimes break; 2751556Srgrimes } 2761556Srgrimesout: 2771556Srgrimes if (pendingsigs) 2781556Srgrimes dotrap(); 27952526Scracauer /* 28052526Scracauer * XXX - Like "!(n->type == NSEMI)", more types will probably 28152526Scracauer * need to be excluded from this test. It's probably better 28252526Scracauer * to set or unset EV_TESTED in the loop above than to bloat 28352526Scracauer * the conditional here. 28452526Scracauer */ 28552526Scracauer if ((flags & EV_EXIT) || (eflag && exitstatus 28652526Scracauer && !(flags & EV_TESTED) && !(n->type == NSEMI))) 2871556Srgrimes exitshell(exitstatus); 2881556Srgrimes} 2891556Srgrimes 2901556Srgrimes 2911556SrgrimesSTATIC void 2921556Srgrimesevalloop(n) 2931556Srgrimes union node *n; 29417987Speter{ 2951556Srgrimes int status; 2961556Srgrimes 2971556Srgrimes loopnest++; 2981556Srgrimes status = 0; 2991556Srgrimes for (;;) { 3001556Srgrimes evaltree(n->nbinary.ch1, EV_TESTED); 3011556Srgrimes if (evalskip) { 3021556Srgrimesskipping: if (evalskip == SKIPCONT && --skipcount <= 0) { 3031556Srgrimes evalskip = 0; 3041556Srgrimes continue; 3051556Srgrimes } 3061556Srgrimes if (evalskip == SKIPBREAK && --skipcount <= 0) 3071556Srgrimes evalskip = 0; 3081556Srgrimes break; 3091556Srgrimes } 3101556Srgrimes if (n->type == NWHILE) { 3111556Srgrimes if (exitstatus != 0) 3121556Srgrimes break; 3131556Srgrimes } else { 3141556Srgrimes if (exitstatus == 0) 3151556Srgrimes break; 3161556Srgrimes } 3171556Srgrimes evaltree(n->nbinary.ch2, 0); 3181556Srgrimes status = exitstatus; 3191556Srgrimes if (evalskip) 3201556Srgrimes goto skipping; 3211556Srgrimes } 3221556Srgrimes loopnest--; 3231556Srgrimes exitstatus = status; 3241556Srgrimes} 3251556Srgrimes 3261556Srgrimes 3271556Srgrimes 3281556SrgrimesSTATIC void 3291556Srgrimesevalfor(n) 33017987Speter union node *n; 33117987Speter{ 3321556Srgrimes struct arglist arglist; 3331556Srgrimes union node *argp; 3341556Srgrimes struct strlist *sp; 3351556Srgrimes struct stackmark smark; 3361556Srgrimes 3371556Srgrimes setstackmark(&smark); 3381556Srgrimes arglist.lastp = &arglist.list; 3391556Srgrimes for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { 34017987Speter oexitstatus = exitstatus; 3411556Srgrimes expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 3421556Srgrimes if (evalskip) 3431556Srgrimes goto out; 3441556Srgrimes } 3451556Srgrimes *arglist.lastp = NULL; 3461556Srgrimes 3471556Srgrimes exitstatus = 0; 3481556Srgrimes loopnest++; 3491556Srgrimes for (sp = arglist.list ; sp ; sp = sp->next) { 3501556Srgrimes setvar(n->nfor.var, sp->text, 0); 3511556Srgrimes evaltree(n->nfor.body, 0); 3521556Srgrimes if (evalskip) { 3531556Srgrimes if (evalskip == SKIPCONT && --skipcount <= 0) { 3541556Srgrimes evalskip = 0; 3551556Srgrimes continue; 3561556Srgrimes } 3571556Srgrimes if (evalskip == SKIPBREAK && --skipcount <= 0) 3581556Srgrimes evalskip = 0; 3591556Srgrimes break; 3601556Srgrimes } 3611556Srgrimes } 3621556Srgrimes loopnest--; 3631556Srgrimesout: 3641556Srgrimes popstackmark(&smark); 3651556Srgrimes} 3661556Srgrimes 3671556Srgrimes 3681556Srgrimes 3691556SrgrimesSTATIC void 3701556Srgrimesevalcase(n, flags) 3711556Srgrimes union node *n; 37217987Speter int flags; 37317987Speter{ 3741556Srgrimes union node *cp; 3751556Srgrimes union node *patp; 3761556Srgrimes struct arglist arglist; 3771556Srgrimes struct stackmark smark; 3781556Srgrimes 3791556Srgrimes setstackmark(&smark); 3801556Srgrimes arglist.lastp = &arglist.list; 38117987Speter oexitstatus = exitstatus; 3821556Srgrimes expandarg(n->ncase.expr, &arglist, EXP_TILDE); 3831556Srgrimes for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) { 3841556Srgrimes for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { 3851556Srgrimes if (casematch(patp, arglist.list->text)) { 3861556Srgrimes if (evalskip == 0) { 3871556Srgrimes evaltree(cp->nclist.body, flags); 3881556Srgrimes } 3891556Srgrimes goto out; 3901556Srgrimes } 3911556Srgrimes } 3921556Srgrimes } 3931556Srgrimesout: 3941556Srgrimes popstackmark(&smark); 3951556Srgrimes} 3961556Srgrimes 3971556Srgrimes 3981556Srgrimes 3991556Srgrimes/* 4001556Srgrimes * Kick off a subshell to evaluate a tree. 4011556Srgrimes */ 4021556Srgrimes 4031556SrgrimesSTATIC void 4041556Srgrimesevalsubshell(n, flags) 4051556Srgrimes union node *n; 40617987Speter int flags; 40717987Speter{ 4081556Srgrimes struct job *jp; 4091556Srgrimes int backgnd = (n->type == NBACKGND); 4101556Srgrimes 4111556Srgrimes expredir(n->nredir.redirect); 4121556Srgrimes jp = makejob(n, 1); 4131556Srgrimes if (forkshell(jp, n, backgnd) == 0) { 4141556Srgrimes if (backgnd) 4151556Srgrimes flags &=~ EV_TESTED; 4161556Srgrimes redirect(n->nredir.redirect, 0); 4171556Srgrimes evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ 4181556Srgrimes } 4191556Srgrimes if (! backgnd) { 4201556Srgrimes INTOFF; 42145916Scracauer exitstatus = waitforjob(jp, (int *)NULL); 4221556Srgrimes INTON; 4231556Srgrimes } 4241556Srgrimes} 4251556Srgrimes 4261556Srgrimes 4271556Srgrimes 4281556Srgrimes/* 4291556Srgrimes * Compute the names of the files in a redirection list. 4301556Srgrimes */ 4311556Srgrimes 4321556SrgrimesSTATIC void 4331556Srgrimesexpredir(n) 4341556Srgrimes union node *n; 43517987Speter{ 43625222Ssteve union node *redir; 4371556Srgrimes 4381556Srgrimes for (redir = n ; redir ; redir = redir->nfile.next) { 43917987Speter struct arglist fn; 44017987Speter fn.lastp = &fn.list; 44117987Speter oexitstatus = exitstatus; 44217987Speter switch (redir->type) { 44317987Speter case NFROM: 44417987Speter case NTO: 44517987Speter case NAPPEND: 4461556Srgrimes expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); 4471556Srgrimes redir->nfile.expfname = fn.list->text; 44817987Speter break; 44917987Speter case NFROMFD: 45017987Speter case NTOFD: 45117987Speter if (redir->ndup.vname) { 45217987Speter expandarg(redir->ndup.vname, &fn, EXP_FULL | EXP_TILDE); 45317987Speter fixredir(redir, fn.list->text, 1); 45417987Speter } 45517987Speter break; 4561556Srgrimes } 4571556Srgrimes } 4581556Srgrimes} 4591556Srgrimes 4601556Srgrimes 4611556Srgrimes 4621556Srgrimes/* 4631556Srgrimes * Evaluate a pipeline. All the processes in the pipeline are children 4641556Srgrimes * of the process creating the pipeline. (This differs from some versions 4651556Srgrimes * of the shell, which make the last process in a pipeline the parent 4661556Srgrimes * of all the rest.) 4671556Srgrimes */ 4681556Srgrimes 4691556SrgrimesSTATIC void 4701556Srgrimesevalpipe(n) 4711556Srgrimes union node *n; 47217987Speter{ 4731556Srgrimes struct job *jp; 4741556Srgrimes struct nodelist *lp; 4751556Srgrimes int pipelen; 4761556Srgrimes int prevfd; 4771556Srgrimes int pip[2]; 4781556Srgrimes 47917987Speter TRACE(("evalpipe(0x%lx) called\n", (long)n)); 4801556Srgrimes pipelen = 0; 4811556Srgrimes for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) 4821556Srgrimes pipelen++; 4831556Srgrimes INTOFF; 4841556Srgrimes jp = makejob(n, pipelen); 4851556Srgrimes prevfd = -1; 4861556Srgrimes for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 4871556Srgrimes prehash(lp->n); 4881556Srgrimes pip[1] = -1; 4891556Srgrimes if (lp->next) { 4901556Srgrimes if (pipe(pip) < 0) { 4911556Srgrimes close(prevfd); 49253891Scracauer error("Pipe call failed: %s", strerror(errno)); 4931556Srgrimes } 4941556Srgrimes } 4951556Srgrimes if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { 4961556Srgrimes INTON; 4971556Srgrimes if (prevfd > 0) { 4981556Srgrimes close(0); 4991556Srgrimes copyfd(prevfd, 0); 5001556Srgrimes close(prevfd); 5011556Srgrimes } 5021556Srgrimes if (pip[1] >= 0) { 50353282Scracauer if (!(prevfd >= 0 && pip[0] == 0)) 50452900Scracauer close(pip[0]); 5051556Srgrimes if (pip[1] != 1) { 5061556Srgrimes close(1); 5071556Srgrimes copyfd(pip[1], 1); 5081556Srgrimes close(pip[1]); 5091556Srgrimes } 5101556Srgrimes } 5111556Srgrimes evaltree(lp->n, EV_EXIT); 5121556Srgrimes } 5131556Srgrimes if (prevfd >= 0) 5141556Srgrimes close(prevfd); 5151556Srgrimes prevfd = pip[0]; 5161556Srgrimes close(pip[1]); 5171556Srgrimes } 5181556Srgrimes INTON; 5191556Srgrimes if (n->npipe.backgnd == 0) { 5201556Srgrimes INTOFF; 52145916Scracauer exitstatus = waitforjob(jp, (int *)NULL); 5221556Srgrimes TRACE(("evalpipe: job done exit status %d\n", exitstatus)); 5231556Srgrimes INTON; 5241556Srgrimes } 5251556Srgrimes} 5261556Srgrimes 5271556Srgrimes 5281556Srgrimes 5291556Srgrimes/* 5301556Srgrimes * Execute a command inside back quotes. If it's a builtin command, we 5311556Srgrimes * want to save its output in a block obtained from malloc. Otherwise 5321556Srgrimes * we fork off a subprocess and get the output of the command via a pipe. 5331556Srgrimes * Should be called with interrupts off. 5341556Srgrimes */ 5351556Srgrimes 5361556Srgrimesvoid 5371556Srgrimesevalbackcmd(n, result) 5381556Srgrimes union node *n; 5391556Srgrimes struct backcmd *result; 54017987Speter{ 5411556Srgrimes int pip[2]; 5421556Srgrimes struct job *jp; 5431556Srgrimes struct stackmark smark; /* unnecessary */ 5441556Srgrimes 5451556Srgrimes setstackmark(&smark); 5461556Srgrimes result->fd = -1; 5471556Srgrimes result->buf = NULL; 5481556Srgrimes result->nleft = 0; 5491556Srgrimes result->jp = NULL; 55017987Speter if (n == NULL) { 55117987Speter exitstatus = 0; 5521556Srgrimes goto out; 55317987Speter } 5541556Srgrimes if (n->type == NCMD) { 55517987Speter exitstatus = oexitstatus; 5561556Srgrimes evalcommand(n, EV_BACKCMD, result); 5571556Srgrimes } else { 55817987Speter exitstatus = 0; 5591556Srgrimes if (pipe(pip) < 0) 56053891Scracauer error("Pipe call failed: %s", strerror(errno)); 5611556Srgrimes jp = makejob(n, 1); 5621556Srgrimes if (forkshell(jp, n, FORK_NOJOB) == 0) { 5631556Srgrimes FORCEINTON; 5641556Srgrimes close(pip[0]); 5651556Srgrimes if (pip[1] != 1) { 5661556Srgrimes close(1); 5671556Srgrimes copyfd(pip[1], 1); 5681556Srgrimes close(pip[1]); 5691556Srgrimes } 5701556Srgrimes evaltree(n, EV_EXIT); 5711556Srgrimes } 5721556Srgrimes close(pip[1]); 5731556Srgrimes result->fd = pip[0]; 5741556Srgrimes result->jp = jp; 5751556Srgrimes } 5761556Srgrimesout: 5771556Srgrimes popstackmark(&smark); 5781556Srgrimes TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n", 5791556Srgrimes result->fd, result->buf, result->nleft, result->jp)); 5801556Srgrimes} 5811556Srgrimes 5821556Srgrimes 5831556Srgrimes 5841556Srgrimes/* 5851556Srgrimes * Execute a simple command. 5861556Srgrimes */ 5871556Srgrimes 5881556SrgrimesSTATIC void 5891556Srgrimesevalcommand(cmd, flags, backcmd) 5901556Srgrimes union node *cmd; 59117987Speter int flags; 5921556Srgrimes struct backcmd *backcmd; 59317987Speter{ 5941556Srgrimes struct stackmark smark; 5951556Srgrimes union node *argp; 5961556Srgrimes struct arglist arglist; 5971556Srgrimes struct arglist varlist; 5981556Srgrimes char **argv; 5991556Srgrimes int argc; 6001556Srgrimes char **envp; 6011556Srgrimes int varflag; 6021556Srgrimes struct strlist *sp; 6031556Srgrimes int mode; 6041556Srgrimes int pip[2]; 6051556Srgrimes struct cmdentry cmdentry; 6061556Srgrimes struct job *jp; 6071556Srgrimes struct jmploc jmploc; 6081556Srgrimes struct jmploc *volatile savehandler; 6091556Srgrimes char *volatile savecmdname; 6101556Srgrimes volatile struct shparam saveparam; 6111556Srgrimes struct localvar *volatile savelocalvars; 6121556Srgrimes volatile int e; 6131556Srgrimes char *lastarg; 61445916Scracauer int realstatus; 61517987Speter#if __GNUC__ 61617987Speter /* Avoid longjmp clobbering */ 61717987Speter (void) &argv; 61817987Speter (void) &argc; 61917987Speter (void) &lastarg; 62017987Speter (void) &flags; 62117987Speter#endif 6221556Srgrimes 6231556Srgrimes /* First expand the arguments. */ 62417987Speter TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags)); 6251556Srgrimes setstackmark(&smark); 6261556Srgrimes arglist.lastp = &arglist.list; 6271556Srgrimes varlist.lastp = &varlist.list; 6281556Srgrimes varflag = 1; 62917987Speter oexitstatus = exitstatus; 63017987Speter exitstatus = 0; 6311556Srgrimes for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 63217987Speter char *p = argp->narg.text; 6331556Srgrimes if (varflag && is_name(*p)) { 6341556Srgrimes do { 6351556Srgrimes p++; 6361556Srgrimes } while (is_in_name(*p)); 6371556Srgrimes if (*p == '=') { 6381556Srgrimes expandarg(argp, &varlist, EXP_VARTILDE); 6391556Srgrimes continue; 6401556Srgrimes } 6411556Srgrimes } 6421556Srgrimes expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 6431556Srgrimes varflag = 0; 6441556Srgrimes } 6451556Srgrimes *arglist.lastp = NULL; 6461556Srgrimes *varlist.lastp = NULL; 6471556Srgrimes expredir(cmd->ncmd.redirect); 6481556Srgrimes argc = 0; 6491556Srgrimes for (sp = arglist.list ; sp ; sp = sp->next) 6501556Srgrimes argc++; 6511556Srgrimes argv = stalloc(sizeof (char *) * (argc + 1)); 6521556Srgrimes 6531556Srgrimes for (sp = arglist.list ; sp ; sp = sp->next) { 6541556Srgrimes TRACE(("evalcommand arg: %s\n", sp->text)); 6551556Srgrimes *argv++ = sp->text; 6561556Srgrimes } 6571556Srgrimes *argv = NULL; 6581556Srgrimes lastarg = NULL; 6591556Srgrimes if (iflag && funcnest == 0 && argc > 0) 6601556Srgrimes lastarg = argv[-1]; 6611556Srgrimes argv -= argc; 6621556Srgrimes 6631556Srgrimes /* Print the command if xflag is set. */ 6641556Srgrimes if (xflag) { 6651556Srgrimes outc('+', &errout); 6661556Srgrimes for (sp = varlist.list ; sp ; sp = sp->next) { 6671556Srgrimes outc(' ', &errout); 6681556Srgrimes out2str(sp->text); 6691556Srgrimes } 6701556Srgrimes for (sp = arglist.list ; sp ; sp = sp->next) { 6711556Srgrimes outc(' ', &errout); 6721556Srgrimes out2str(sp->text); 6731556Srgrimes } 6741556Srgrimes outc('\n', &errout); 6751556Srgrimes flushout(&errout); 6761556Srgrimes } 6771556Srgrimes 6781556Srgrimes /* Now locate the command. */ 6791556Srgrimes if (argc == 0) { 6801556Srgrimes cmdentry.cmdtype = CMDBUILTIN; 6811556Srgrimes cmdentry.u.index = BLTINCMD; 6821556Srgrimes } else { 68317987Speter static const char PATH[] = "PATH="; 68417987Speter char *path = pathval(); 68517987Speter 68617987Speter /* 68717987Speter * Modify the command lookup path, if a PATH= assignment 68817987Speter * is present 68917987Speter */ 69017987Speter for (sp = varlist.list ; sp ; sp = sp->next) 69117987Speter if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) 69217987Speter path = sp->text + sizeof(PATH) - 1; 69317987Speter 69417987Speter find_command(argv[0], &cmdentry, 1, path); 6951556Srgrimes if (cmdentry.cmdtype == CMDUNKNOWN) { /* command not found */ 69620425Ssteve exitstatus = 127; 6971556Srgrimes flushout(&errout); 6981556Srgrimes return; 6991556Srgrimes } 7001556Srgrimes /* implement the bltin builtin here */ 7011556Srgrimes if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == BLTINCMD) { 7021556Srgrimes for (;;) { 7031556Srgrimes argv++; 7041556Srgrimes if (--argc == 0) 7051556Srgrimes break; 7061556Srgrimes if ((cmdentry.u.index = find_builtin(*argv)) < 0) { 7071556Srgrimes outfmt(&errout, "%s: not found\n", *argv); 70820425Ssteve exitstatus = 127; 7091556Srgrimes flushout(&errout); 7101556Srgrimes return; 7111556Srgrimes } 7121556Srgrimes if (cmdentry.u.index != BLTINCMD) 7131556Srgrimes break; 7141556Srgrimes } 7151556Srgrimes } 7161556Srgrimes } 7171556Srgrimes 7181556Srgrimes /* Fork off a child process if necessary. */ 7191556Srgrimes if (cmd->ncmd.backgnd 72045221Scracauer || (cmdentry.cmdtype == CMDNORMAL 72145221Scracauer && ((flags & EV_EXIT) == 0 || Tflag)) 72217987Speter || ((flags & EV_BACKCMD) != 0 7231556Srgrimes && (cmdentry.cmdtype != CMDBUILTIN 72448896Ssheldonh || cmdentry.u.index == CDCMD 7251556Srgrimes || cmdentry.u.index == DOTCMD 72617987Speter || cmdentry.u.index == EVALCMD))) { 7271556Srgrimes jp = makejob(cmd, 1); 7281556Srgrimes mode = cmd->ncmd.backgnd; 7291556Srgrimes if (flags & EV_BACKCMD) { 7301556Srgrimes mode = FORK_NOJOB; 7311556Srgrimes if (pipe(pip) < 0) 73253891Scracauer error("Pipe call failed: %s", strerror(errno)); 7331556Srgrimes } 7341556Srgrimes if (forkshell(jp, cmd, mode) != 0) 7351556Srgrimes goto parent; /* at end of routine */ 7361556Srgrimes if (flags & EV_BACKCMD) { 7371556Srgrimes FORCEINTON; 7381556Srgrimes close(pip[0]); 7391556Srgrimes if (pip[1] != 1) { 7401556Srgrimes close(1); 7411556Srgrimes copyfd(pip[1], 1); 7421556Srgrimes close(pip[1]); 7431556Srgrimes } 7441556Srgrimes } 7451556Srgrimes flags |= EV_EXIT; 7461556Srgrimes } 7471556Srgrimes 7481556Srgrimes /* This is the child process if a fork occurred. */ 7491556Srgrimes /* Execute the command. */ 7501556Srgrimes if (cmdentry.cmdtype == CMDFUNCTION) { 75120425Ssteve#ifdef DEBUG 7521556Srgrimes trputs("Shell function: "); trargs(argv); 75320425Ssteve#endif 7541556Srgrimes redirect(cmd->ncmd.redirect, REDIR_PUSH); 7551556Srgrimes saveparam = shellparam; 7561556Srgrimes shellparam.malloc = 0; 75720425Ssteve shellparam.reset = 1; 7581556Srgrimes shellparam.nparam = argc - 1; 7591556Srgrimes shellparam.p = argv + 1; 7601556Srgrimes shellparam.optnext = NULL; 7611556Srgrimes INTOFF; 7621556Srgrimes savelocalvars = localvars; 7631556Srgrimes localvars = NULL; 7641556Srgrimes INTON; 7651556Srgrimes if (setjmp(jmploc.loc)) { 7661556Srgrimes if (exception == EXSHELLPROC) 7671556Srgrimes freeparam((struct shparam *)&saveparam); 7681556Srgrimes else { 7691556Srgrimes freeparam(&shellparam); 7701556Srgrimes shellparam = saveparam; 7711556Srgrimes } 7721556Srgrimes poplocalvars(); 7731556Srgrimes localvars = savelocalvars; 7741556Srgrimes handler = savehandler; 7751556Srgrimes longjmp(handler->loc, 1); 7761556Srgrimes } 7771556Srgrimes savehandler = handler; 7781556Srgrimes handler = &jmploc; 7791556Srgrimes for (sp = varlist.list ; sp ; sp = sp->next) 7801556Srgrimes mklocal(sp->text); 7811556Srgrimes funcnest++; 78235675Scracauer if (flags & EV_TESTED) 78335675Scracauer evaltree(cmdentry.u.func, EV_TESTED); 78435675Scracauer else 78535675Scracauer evaltree(cmdentry.u.func, 0); 7861556Srgrimes funcnest--; 7871556Srgrimes INTOFF; 7881556Srgrimes poplocalvars(); 7891556Srgrimes localvars = savelocalvars; 7901556Srgrimes freeparam(&shellparam); 7911556Srgrimes shellparam = saveparam; 7921556Srgrimes handler = savehandler; 7931556Srgrimes popredir(); 7941556Srgrimes INTON; 7951556Srgrimes if (evalskip == SKIPFUNC) { 7961556Srgrimes evalskip = 0; 7971556Srgrimes skipcount = 0; 7981556Srgrimes } 7991556Srgrimes if (flags & EV_EXIT) 8001556Srgrimes exitshell(exitstatus); 8011556Srgrimes } else if (cmdentry.cmdtype == CMDBUILTIN) { 80220425Ssteve#ifdef DEBUG 8031556Srgrimes trputs("builtin command: "); trargs(argv); 80420425Ssteve#endif 8051556Srgrimes mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; 8061556Srgrimes if (flags == EV_BACKCMD) { 8071556Srgrimes memout.nleft = 0; 8081556Srgrimes memout.nextc = memout.buf; 8091556Srgrimes memout.bufsize = 64; 8101556Srgrimes mode |= REDIR_BACKQ; 8111556Srgrimes } 8121556Srgrimes redirect(cmd->ncmd.redirect, mode); 8131556Srgrimes savecmdname = commandname; 8141556Srgrimes cmdenviron = varlist.list; 8151556Srgrimes e = -1; 8161556Srgrimes if (setjmp(jmploc.loc)) { 8171556Srgrimes e = exception; 8181556Srgrimes exitstatus = (e == EXINT)? SIGINT+128 : 2; 8191556Srgrimes goto cmddone; 8201556Srgrimes } 8211556Srgrimes savehandler = handler; 8221556Srgrimes handler = &jmploc; 8231556Srgrimes commandname = argv[0]; 8241556Srgrimes argptr = argv + 1; 8251556Srgrimes optptr = NULL; /* initialize nextopt */ 8261556Srgrimes exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); 8271556Srgrimes flushall(); 8281556Srgrimescmddone: 8291556Srgrimes out1 = &output; 8301556Srgrimes out2 = &errout; 8311556Srgrimes freestdout(); 8321556Srgrimes if (e != EXSHELLPROC) { 8331556Srgrimes commandname = savecmdname; 8341556Srgrimes if (flags & EV_EXIT) { 8351556Srgrimes exitshell(exitstatus); 8361556Srgrimes } 8371556Srgrimes } 8381556Srgrimes handler = savehandler; 8391556Srgrimes if (e != -1) { 84020425Ssteve if ((e != EXERROR && e != EXEXEC) 84120425Ssteve || cmdentry.u.index == BLTINCMD 84220425Ssteve || cmdentry.u.index == DOTCMD 84320425Ssteve || cmdentry.u.index == EVALCMD 84417987Speter#ifndef NO_HISTORY 84520425Ssteve || cmdentry.u.index == HISTCMD 84617987Speter#endif 84720425Ssteve || cmdentry.u.index == EXECCMD) 8481556Srgrimes exraise(e); 8491556Srgrimes FORCEINTON; 8501556Srgrimes } 8511556Srgrimes if (cmdentry.u.index != EXECCMD) 8521556Srgrimes popredir(); 8531556Srgrimes if (flags == EV_BACKCMD) { 8541556Srgrimes backcmd->buf = memout.buf; 8551556Srgrimes backcmd->nleft = memout.nextc - memout.buf; 8561556Srgrimes memout.buf = NULL; 8571556Srgrimes } 8581556Srgrimes } else { 85920425Ssteve#ifdef DEBUG 8601556Srgrimes trputs("normal command: "); trargs(argv); 86120425Ssteve#endif 8621556Srgrimes clearredir(); 8631556Srgrimes redirect(cmd->ncmd.redirect, 0); 8641556Srgrimes for (sp = varlist.list ; sp ; sp = sp->next) 8651556Srgrimes setvareq(sp->text, VEXPORT|VSTACK); 8661556Srgrimes envp = environment(); 86717987Speter shellexec(argv, envp, pathval(), cmdentry.u.index); 8681556Srgrimes /*NOTREACHED*/ 8691556Srgrimes } 8701556Srgrimes goto out; 8711556Srgrimes 8721556Srgrimesparent: /* parent process gets here (if we forked) */ 8731556Srgrimes if (mode == 0) { /* argument to fork */ 8741556Srgrimes INTOFF; 87545916Scracauer exitstatus = waitforjob(jp, &realstatus); 8761556Srgrimes INTON; 87745916Scracauer if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) { 87845266Scracauer evalskip = SKIPBREAK; 87945266Scracauer skipcount = loopnest; 88045266Scracauer } 8811556Srgrimes } else if (mode == 2) { 8821556Srgrimes backcmd->fd = pip[0]; 8831556Srgrimes close(pip[1]); 8841556Srgrimes backcmd->jp = jp; 8851556Srgrimes } 8861556Srgrimes 8871556Srgrimesout: 8881556Srgrimes if (lastarg) 8891556Srgrimes setvar("_", lastarg, 0); 8901556Srgrimes popstackmark(&smark); 8911556Srgrimes} 8921556Srgrimes 8931556Srgrimes 8941556Srgrimes 8951556Srgrimes/* 8961556Srgrimes * Search for a command. This is called before we fork so that the 8971556Srgrimes * location of the command will be available in the parent as well as 8981556Srgrimes * the child. The check for "goodname" is an overly conservative 8991556Srgrimes * check that the name will not be subject to expansion. 9001556Srgrimes */ 9011556Srgrimes 9021556SrgrimesSTATIC void 9031556Srgrimesprehash(n) 9041556Srgrimes union node *n; 90517987Speter{ 9061556Srgrimes struct cmdentry entry; 9071556Srgrimes 90817987Speter if (n->type == NCMD && n->ncmd.args) 90917987Speter if (goodname(n->ncmd.args->narg.text)) 91017987Speter find_command(n->ncmd.args->narg.text, &entry, 0, 91117987Speter pathval()); 9121556Srgrimes} 9131556Srgrimes 9141556Srgrimes 9151556Srgrimes 9161556Srgrimes/* 9171556Srgrimes * Builtin commands. Builtin commands whose functions are closely 9181556Srgrimes * tied to evaluation are implemented here. 9191556Srgrimes */ 9201556Srgrimes 9211556Srgrimes/* 9221556Srgrimes * No command given, or a bltin command with no arguments. Set the 9231556Srgrimes * specified variables. 9241556Srgrimes */ 9251556Srgrimes 92617987Speterint 92717987Speterbltincmd(argc, argv) 92825905Ssteve int argc __unused; 92925905Ssteve char **argv __unused; 93017987Speter{ 9311556Srgrimes listsetvar(cmdenviron); 93220425Ssteve /* 93317987Speter * Preserve exitstatus of a previous possible redirection 93420425Ssteve * as POSIX mandates 93517987Speter */ 9361556Srgrimes return exitstatus; 9371556Srgrimes} 9381556Srgrimes 9391556Srgrimes 9401556Srgrimes/* 9411556Srgrimes * Handle break and continue commands. Break, continue, and return are 9421556Srgrimes * all handled by setting the evalskip flag. The evaluation routines 9431556Srgrimes * above all check this flag, and if it is set they start skipping 9441556Srgrimes * commands rather than executing them. The variable skipcount is 9451556Srgrimes * the number of loops to break/continue, or the number of function 9461556Srgrimes * levels to return. (The latter is always 1.) It should probably 9471556Srgrimes * be an error to break out of more loops than exist, but it isn't 9481556Srgrimes * in the standard shell so we don't make it one here. 9491556Srgrimes */ 9501556Srgrimes 95117987Speterint 95217987Speterbreakcmd(argc, argv) 95317987Speter int argc; 95420425Ssteve char **argv; 95517987Speter{ 95620425Ssteve int n = argc > 1 ? number(argv[1]) : 1; 9571556Srgrimes 9581556Srgrimes if (n > loopnest) 9591556Srgrimes n = loopnest; 9601556Srgrimes if (n > 0) { 9611556Srgrimes evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 9621556Srgrimes skipcount = n; 9631556Srgrimes } 9641556Srgrimes return 0; 9651556Srgrimes} 9661556Srgrimes 9671556Srgrimes 9681556Srgrimes/* 9691556Srgrimes * The return command. 9701556Srgrimes */ 9711556Srgrimes 97217987Speterint 97320425Sstevereturncmd(argc, argv) 97417987Speter int argc; 97520425Ssteve char **argv; 97617987Speter{ 97720425Ssteve int ret = argc > 1 ? number(argv[1]) : oexitstatus; 9781556Srgrimes 9791556Srgrimes if (funcnest) { 9801556Srgrimes evalskip = SKIPFUNC; 9811556Srgrimes skipcount = 1; 98220425Ssteve } else { 98320425Ssteve /* skip the rest of the file */ 98420425Ssteve evalskip = SKIPFILE; 98520425Ssteve skipcount = 1; 9861556Srgrimes } 9871556Srgrimes return ret; 9881556Srgrimes} 9891556Srgrimes 9901556Srgrimes 99117987Speterint 99220425Sstevefalsecmd(argc, argv) 99325905Ssteve int argc __unused; 99425905Ssteve char **argv __unused; 99517987Speter{ 99617987Speter return 1; 99717987Speter} 99817987Speter 99917987Speter 100017987Speterint 100120425Sstevetruecmd(argc, argv) 100225905Ssteve int argc __unused; 100325905Ssteve char **argv __unused; 100417987Speter{ 10051556Srgrimes return 0; 10061556Srgrimes} 10071556Srgrimes 10081556Srgrimes 100917987Speterint 101020425Ssteveexeccmd(argc, argv) 101117987Speter int argc; 101220425Ssteve char **argv; 101317987Speter{ 10141556Srgrimes if (argc > 1) { 101517987Speter struct strlist *sp; 101617987Speter 10171556Srgrimes iflag = 0; /* exit on error */ 10181556Srgrimes mflag = 0; 10191556Srgrimes optschanged(); 102017987Speter for (sp = cmdenviron; sp ; sp = sp->next) 102117987Speter setvareq(sp->text, VEXPORT|VSTACK); 10221556Srgrimes shellexec(argv + 1, environment(), pathval(), 0); 10231556Srgrimes 10241556Srgrimes } 10251556Srgrimes return 0; 10261556Srgrimes} 1027