eval.c revision 18754
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. 353044Sdg * 3618754Ssteve * $Id: eval.c,v 1.5 1996/09/01 10:19:57 peter Exp $ 371556Srgrimes */ 381556Srgrimes 391556Srgrimes#ifndef lint 4017987Speterstatic char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95"; 411556Srgrimes#endif /* not lint */ 421556Srgrimes 4317987Speter#include <signal.h> 4417987Speter#include <unistd.h> 4517987Speter 461556Srgrimes/* 471556Srgrimes * Evaluate a command. 481556Srgrimes */ 491556Srgrimes 501556Srgrimes#include "shell.h" 511556Srgrimes#include "nodes.h" 521556Srgrimes#include "syntax.h" 531556Srgrimes#include "expand.h" 541556Srgrimes#include "parser.h" 551556Srgrimes#include "jobs.h" 561556Srgrimes#include "eval.h" 571556Srgrimes#include "builtins.h" 581556Srgrimes#include "options.h" 591556Srgrimes#include "exec.h" 601556Srgrimes#include "redir.h" 611556Srgrimes#include "input.h" 621556Srgrimes#include "output.h" 631556Srgrimes#include "trap.h" 641556Srgrimes#include "var.h" 651556Srgrimes#include "memalloc.h" 661556Srgrimes#include "error.h" 6717987Speter#include "show.h" 681556Srgrimes#include "mystring.h" 6917987Speter#ifndef NO_HISTORY 701556Srgrimes#include "myhistedit.h" 7117987Speter#endif 721556Srgrimes 731556Srgrimes 741556Srgrimes/* flags in argument to evaltree */ 751556Srgrimes#define EV_EXIT 01 /* exit after evaluating tree */ 761556Srgrimes#define EV_TESTED 02 /* exit status is checked; ignore -e flag */ 771556Srgrimes#define EV_BACKCMD 04 /* command executing within back quotes */ 781556Srgrimes 791556Srgrimes 801556Srgrimes/* reasons for skipping commands (see comment on breakcmd routine) */ 811556Srgrimes#define SKIPBREAK 1 821556Srgrimes#define SKIPCONT 2 831556Srgrimes#define SKIPFUNC 3 841556Srgrimes 851556SrgrimesMKINIT int evalskip; /* set if we are skipping commands */ 861556SrgrimesSTATIC int skipcount; /* number of levels to skip */ 871556SrgrimesMKINIT int loopnest; /* current loop nesting level */ 881556Srgrimesint funcnest; /* depth of function calls */ 891556Srgrimes 901556Srgrimes 911556Srgrimeschar *commandname; 921556Srgrimesstruct strlist *cmdenviron; 931556Srgrimesint exitstatus; /* exit status of last command */ 9417987Speterint oexitstatus; /* saved exit status */ 951556Srgrimes 961556Srgrimes 9717987SpeterSTATIC void evalloop __P((union node *)); 9817987SpeterSTATIC void evalfor __P((union node *)); 9917987SpeterSTATIC void evalcase __P((union node *, int)); 10017987SpeterSTATIC void evalsubshell __P((union node *, int)); 10117987SpeterSTATIC void expredir __P((union node *)); 10217987SpeterSTATIC void evalpipe __P((union node *)); 10317987SpeterSTATIC void evalcommand __P((union node *, int, struct backcmd *)); 10417987SpeterSTATIC void prehash __P((union node *)); 1051556Srgrimes 1061556Srgrimes 1071556Srgrimes/* 1081556Srgrimes * Called to reset things after an exception. 1091556Srgrimes */ 1101556Srgrimes 1111556Srgrimes#ifdef mkinit 1121556SrgrimesINCLUDE "eval.h" 1131556Srgrimes 1141556SrgrimesRESET { 1151556Srgrimes evalskip = 0; 1161556Srgrimes loopnest = 0; 1171556Srgrimes funcnest = 0; 1181556Srgrimes} 1191556Srgrimes 1201556SrgrimesSHELLPROC { 1211556Srgrimes exitstatus = 0; 1221556Srgrimes} 1231556Srgrimes#endif 1241556Srgrimes 1251556Srgrimes 1261556Srgrimes 1271556Srgrimes/* 1281556Srgrimes * The eval commmand. 1291556Srgrimes */ 1301556Srgrimes 13117987Speterint 13217987Speterevalcmd(argc, argv) 13317987Speter int argc; 13417987Speter char **argv; 1351556Srgrimes{ 1361556Srgrimes char *p; 1371556Srgrimes char *concat; 1381556Srgrimes char **ap; 1391556Srgrimes 1401556Srgrimes if (argc > 1) { 1411556Srgrimes p = argv[1]; 1421556Srgrimes if (argc > 2) { 1431556Srgrimes STARTSTACKSTR(concat); 1441556Srgrimes ap = argv + 2; 1451556Srgrimes for (;;) { 1461556Srgrimes while (*p) 1471556Srgrimes STPUTC(*p++, concat); 1481556Srgrimes if ((p = *ap++) == NULL) 1491556Srgrimes break; 1501556Srgrimes STPUTC(' ', concat); 1511556Srgrimes } 1521556Srgrimes STPUTC('\0', concat); 1531556Srgrimes p = grabstackstr(concat); 1541556Srgrimes } 1551556Srgrimes evalstring(p); 1561556Srgrimes } 1571556Srgrimes return exitstatus; 1581556Srgrimes} 1591556Srgrimes 1601556Srgrimes 1611556Srgrimes/* 1621556Srgrimes * Execute a command or commands contained in a string. 1631556Srgrimes */ 1641556Srgrimes 1651556Srgrimesvoid 1661556Srgrimesevalstring(s) 1671556Srgrimes char *s; 1681556Srgrimes { 1691556Srgrimes union node *n; 1701556Srgrimes struct stackmark smark; 1711556Srgrimes 1721556Srgrimes setstackmark(&smark); 1731556Srgrimes setinputstring(s, 1); 1741556Srgrimes while ((n = parsecmd(0)) != NEOF) { 1751556Srgrimes evaltree(n, 0); 1761556Srgrimes popstackmark(&smark); 1771556Srgrimes } 1781556Srgrimes popfile(); 1791556Srgrimes popstackmark(&smark); 1801556Srgrimes} 1811556Srgrimes 1821556Srgrimes 1831556Srgrimes 1841556Srgrimes/* 1851556Srgrimes * Evaluate a parse tree. The value is left in the global variable 1861556Srgrimes * exitstatus. 1871556Srgrimes */ 1881556Srgrimes 1891556Srgrimesvoid 1901556Srgrimesevaltree(n, flags) 1911556Srgrimes union node *n; 19217987Speter int flags; 19317987Speter{ 1941556Srgrimes if (n == NULL) { 1951556Srgrimes TRACE(("evaltree(NULL) called\n")); 1961556Srgrimes exitstatus = 0; 1971556Srgrimes goto out; 1981556Srgrimes } 19917987Speter#ifndef NO_HISTORY 2001556Srgrimes displayhist = 1; /* show history substitutions done with fc */ 20117987Speter#endif 20217987Speter TRACE(("evaltree(0x%lx: %d) called\n", (long)n, n->type)); 2031556Srgrimes switch (n->type) { 2041556Srgrimes case NSEMI: 2051556Srgrimes evaltree(n->nbinary.ch1, 0); 2061556Srgrimes if (evalskip) 2071556Srgrimes goto out; 2081556Srgrimes evaltree(n->nbinary.ch2, flags); 2091556Srgrimes break; 2101556Srgrimes case NAND: 2111556Srgrimes evaltree(n->nbinary.ch1, EV_TESTED); 21218754Ssteve if (evalskip || exitstatus != 0) { 21318754Ssteve /* don't bomb out on "set -e; false && true" */ 21418754Ssteve flags |= EV_TESTED; 2151556Srgrimes goto out; 21618754Ssteve } 2171556Srgrimes evaltree(n->nbinary.ch2, flags); 2181556Srgrimes break; 2191556Srgrimes case NOR: 2201556Srgrimes evaltree(n->nbinary.ch1, EV_TESTED); 2211556Srgrimes if (evalskip || exitstatus == 0) 2221556Srgrimes goto out; 2231556Srgrimes evaltree(n->nbinary.ch2, flags); 2241556Srgrimes break; 2251556Srgrimes case NREDIR: 2261556Srgrimes expredir(n->nredir.redirect); 2271556Srgrimes redirect(n->nredir.redirect, REDIR_PUSH); 2281556Srgrimes evaltree(n->nredir.n, flags); 2291556Srgrimes popredir(); 2301556Srgrimes break; 2311556Srgrimes case NSUBSHELL: 2321556Srgrimes evalsubshell(n, flags); 2331556Srgrimes break; 2341556Srgrimes case NBACKGND: 2351556Srgrimes evalsubshell(n, flags); 2361556Srgrimes break; 2371556Srgrimes case NIF: { 23817987Speter int status; 2391556Srgrimes 2401556Srgrimes evaltree(n->nif.test, EV_TESTED); 24117987Speter status = exitstatus; 24217987Speter exitstatus = 0; 2431556Srgrimes if (evalskip) 2441556Srgrimes goto out; 24517987Speter if (status == 0) 2461556Srgrimes evaltree(n->nif.ifpart, flags); 24717987Speter else if (n->nif.elsepart) 2481556Srgrimes evaltree(n->nif.elsepart, flags); 2491556Srgrimes break; 2501556Srgrimes } 2511556Srgrimes case NWHILE: 2521556Srgrimes case NUNTIL: 2531556Srgrimes evalloop(n); 2541556Srgrimes break; 2551556Srgrimes case NFOR: 2561556Srgrimes evalfor(n); 2571556Srgrimes break; 2581556Srgrimes case NCASE: 2591556Srgrimes evalcase(n, flags); 2601556Srgrimes break; 2611556Srgrimes case NDEFUN: 2621556Srgrimes defun(n->narg.text, n->narg.next); 2631556Srgrimes exitstatus = 0; 2641556Srgrimes break; 2651556Srgrimes case NNOT: 2661556Srgrimes evaltree(n->nnot.com, EV_TESTED); 2671556Srgrimes exitstatus = !exitstatus; 2681556Srgrimes break; 2691556Srgrimes 2701556Srgrimes case NPIPE: 2711556Srgrimes evalpipe(n); 2721556Srgrimes break; 2731556Srgrimes case NCMD: 2741556Srgrimes evalcommand(n, flags, (struct backcmd *)NULL); 2751556Srgrimes break; 2761556Srgrimes default: 2771556Srgrimes out1fmt("Node type = %d\n", n->type); 2781556Srgrimes flushout(&output); 2791556Srgrimes break; 2801556Srgrimes } 2811556Srgrimesout: 2821556Srgrimes if (pendingsigs) 2831556Srgrimes dotrap(); 2841556Srgrimes if ((flags & EV_EXIT) || (eflag && exitstatus && !(flags & EV_TESTED))) 2851556Srgrimes exitshell(exitstatus); 2861556Srgrimes} 2871556Srgrimes 2881556Srgrimes 2891556SrgrimesSTATIC void 2901556Srgrimesevalloop(n) 2911556Srgrimes union node *n; 29217987Speter{ 2931556Srgrimes int status; 2941556Srgrimes 2951556Srgrimes loopnest++; 2961556Srgrimes status = 0; 2971556Srgrimes for (;;) { 2981556Srgrimes evaltree(n->nbinary.ch1, EV_TESTED); 2991556Srgrimes if (evalskip) { 3001556Srgrimesskipping: if (evalskip == SKIPCONT && --skipcount <= 0) { 3011556Srgrimes evalskip = 0; 3021556Srgrimes continue; 3031556Srgrimes } 3041556Srgrimes if (evalskip == SKIPBREAK && --skipcount <= 0) 3051556Srgrimes evalskip = 0; 3061556Srgrimes break; 3071556Srgrimes } 3081556Srgrimes if (n->type == NWHILE) { 3091556Srgrimes if (exitstatus != 0) 3101556Srgrimes break; 3111556Srgrimes } else { 3121556Srgrimes if (exitstatus == 0) 3131556Srgrimes break; 3141556Srgrimes } 3151556Srgrimes evaltree(n->nbinary.ch2, 0); 3161556Srgrimes status = exitstatus; 3171556Srgrimes if (evalskip) 3181556Srgrimes goto skipping; 3191556Srgrimes } 3201556Srgrimes loopnest--; 3211556Srgrimes exitstatus = status; 3221556Srgrimes} 3231556Srgrimes 3241556Srgrimes 3251556Srgrimes 3261556SrgrimesSTATIC void 3271556Srgrimesevalfor(n) 32817987Speter union node *n; 32917987Speter{ 3301556Srgrimes struct arglist arglist; 3311556Srgrimes union node *argp; 3321556Srgrimes struct strlist *sp; 3331556Srgrimes struct stackmark smark; 3341556Srgrimes 3351556Srgrimes setstackmark(&smark); 3361556Srgrimes arglist.lastp = &arglist.list; 3371556Srgrimes for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { 33817987Speter oexitstatus = exitstatus; 3391556Srgrimes expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 3401556Srgrimes if (evalskip) 3411556Srgrimes goto out; 3421556Srgrimes } 3431556Srgrimes *arglist.lastp = NULL; 3441556Srgrimes 3451556Srgrimes exitstatus = 0; 3461556Srgrimes loopnest++; 3471556Srgrimes for (sp = arglist.list ; sp ; sp = sp->next) { 3481556Srgrimes setvar(n->nfor.var, sp->text, 0); 3491556Srgrimes evaltree(n->nfor.body, 0); 3501556Srgrimes if (evalskip) { 3511556Srgrimes if (evalskip == SKIPCONT && --skipcount <= 0) { 3521556Srgrimes evalskip = 0; 3531556Srgrimes continue; 3541556Srgrimes } 3551556Srgrimes if (evalskip == SKIPBREAK && --skipcount <= 0) 3561556Srgrimes evalskip = 0; 3571556Srgrimes break; 3581556Srgrimes } 3591556Srgrimes } 3601556Srgrimes loopnest--; 3611556Srgrimesout: 3621556Srgrimes popstackmark(&smark); 3631556Srgrimes} 3641556Srgrimes 3651556Srgrimes 3661556Srgrimes 3671556SrgrimesSTATIC void 3681556Srgrimesevalcase(n, flags) 3691556Srgrimes union node *n; 37017987Speter int flags; 37117987Speter{ 3721556Srgrimes union node *cp; 3731556Srgrimes union node *patp; 3741556Srgrimes struct arglist arglist; 3751556Srgrimes struct stackmark smark; 3761556Srgrimes 3771556Srgrimes setstackmark(&smark); 3781556Srgrimes arglist.lastp = &arglist.list; 37917987Speter oexitstatus = exitstatus; 3801556Srgrimes expandarg(n->ncase.expr, &arglist, EXP_TILDE); 3811556Srgrimes for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) { 3821556Srgrimes for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { 3831556Srgrimes if (casematch(patp, arglist.list->text)) { 3841556Srgrimes if (evalskip == 0) { 3851556Srgrimes evaltree(cp->nclist.body, flags); 3861556Srgrimes } 3871556Srgrimes goto out; 3881556Srgrimes } 3891556Srgrimes } 3901556Srgrimes } 3911556Srgrimesout: 3921556Srgrimes popstackmark(&smark); 3931556Srgrimes} 3941556Srgrimes 3951556Srgrimes 3961556Srgrimes 3971556Srgrimes/* 3981556Srgrimes * Kick off a subshell to evaluate a tree. 3991556Srgrimes */ 4001556Srgrimes 4011556SrgrimesSTATIC void 4021556Srgrimesevalsubshell(n, flags) 4031556Srgrimes union node *n; 40417987Speter int flags; 40517987Speter{ 4061556Srgrimes struct job *jp; 4071556Srgrimes int backgnd = (n->type == NBACKGND); 4081556Srgrimes 4091556Srgrimes expredir(n->nredir.redirect); 4101556Srgrimes jp = makejob(n, 1); 4111556Srgrimes if (forkshell(jp, n, backgnd) == 0) { 4121556Srgrimes if (backgnd) 4131556Srgrimes flags &=~ EV_TESTED; 4141556Srgrimes redirect(n->nredir.redirect, 0); 4151556Srgrimes evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ 4161556Srgrimes } 4171556Srgrimes if (! backgnd) { 4181556Srgrimes INTOFF; 4191556Srgrimes exitstatus = waitforjob(jp); 4201556Srgrimes INTON; 4211556Srgrimes } 4221556Srgrimes} 4231556Srgrimes 4241556Srgrimes 4251556Srgrimes 4261556Srgrimes/* 4271556Srgrimes * Compute the names of the files in a redirection list. 4281556Srgrimes */ 4291556Srgrimes 4301556SrgrimesSTATIC void 4311556Srgrimesexpredir(n) 4321556Srgrimes union node *n; 43317987Speter{ 4341556Srgrimes register union node *redir; 4351556Srgrimes 4361556Srgrimes for (redir = n ; redir ; redir = redir->nfile.next) { 43717987Speter struct arglist fn; 43817987Speter fn.lastp = &fn.list; 43917987Speter oexitstatus = exitstatus; 44017987Speter switch (redir->type) { 44117987Speter case NFROM: 44217987Speter case NTO: 44317987Speter case NAPPEND: 4441556Srgrimes expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); 4451556Srgrimes redir->nfile.expfname = fn.list->text; 44617987Speter break; 44717987Speter case NFROMFD: 44817987Speter case NTOFD: 44917987Speter if (redir->ndup.vname) { 45017987Speter expandarg(redir->ndup.vname, &fn, EXP_FULL | EXP_TILDE); 45117987Speter fixredir(redir, fn.list->text, 1); 45217987Speter } 45317987Speter break; 4541556Srgrimes } 4551556Srgrimes } 4561556Srgrimes} 4571556Srgrimes 4581556Srgrimes 4591556Srgrimes 4601556Srgrimes/* 4611556Srgrimes * Evaluate a pipeline. All the processes in the pipeline are children 4621556Srgrimes * of the process creating the pipeline. (This differs from some versions 4631556Srgrimes * of the shell, which make the last process in a pipeline the parent 4641556Srgrimes * of all the rest.) 4651556Srgrimes */ 4661556Srgrimes 4671556SrgrimesSTATIC void 4681556Srgrimesevalpipe(n) 4691556Srgrimes union node *n; 47017987Speter{ 4711556Srgrimes struct job *jp; 4721556Srgrimes struct nodelist *lp; 4731556Srgrimes int pipelen; 4741556Srgrimes int prevfd; 4751556Srgrimes int pip[2]; 4761556Srgrimes 47717987Speter TRACE(("evalpipe(0x%lx) called\n", (long)n)); 4781556Srgrimes pipelen = 0; 4791556Srgrimes for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) 4801556Srgrimes pipelen++; 4811556Srgrimes INTOFF; 4821556Srgrimes jp = makejob(n, pipelen); 4831556Srgrimes prevfd = -1; 4841556Srgrimes for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 4851556Srgrimes prehash(lp->n); 4861556Srgrimes pip[1] = -1; 4871556Srgrimes if (lp->next) { 4881556Srgrimes if (pipe(pip) < 0) { 4891556Srgrimes close(prevfd); 4901556Srgrimes error("Pipe call failed"); 4911556Srgrimes } 4921556Srgrimes } 4931556Srgrimes if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { 4941556Srgrimes INTON; 4951556Srgrimes if (prevfd > 0) { 4961556Srgrimes close(0); 4971556Srgrimes copyfd(prevfd, 0); 4981556Srgrimes close(prevfd); 4991556Srgrimes } 5001556Srgrimes if (pip[1] >= 0) { 5011556Srgrimes close(pip[0]); 5021556Srgrimes if (pip[1] != 1) { 5031556Srgrimes close(1); 5041556Srgrimes copyfd(pip[1], 1); 5051556Srgrimes close(pip[1]); 5061556Srgrimes } 5071556Srgrimes } 5081556Srgrimes evaltree(lp->n, EV_EXIT); 5091556Srgrimes } 5101556Srgrimes if (prevfd >= 0) 5111556Srgrimes close(prevfd); 5121556Srgrimes prevfd = pip[0]; 5131556Srgrimes close(pip[1]); 5141556Srgrimes } 5151556Srgrimes INTON; 5161556Srgrimes if (n->npipe.backgnd == 0) { 5171556Srgrimes INTOFF; 5181556Srgrimes exitstatus = waitforjob(jp); 5191556Srgrimes TRACE(("evalpipe: job done exit status %d\n", exitstatus)); 5201556Srgrimes INTON; 5211556Srgrimes } 5221556Srgrimes} 5231556Srgrimes 5241556Srgrimes 5251556Srgrimes 5261556Srgrimes/* 5271556Srgrimes * Execute a command inside back quotes. If it's a builtin command, we 5281556Srgrimes * want to save its output in a block obtained from malloc. Otherwise 5291556Srgrimes * we fork off a subprocess and get the output of the command via a pipe. 5301556Srgrimes * Should be called with interrupts off. 5311556Srgrimes */ 5321556Srgrimes 5331556Srgrimesvoid 5341556Srgrimesevalbackcmd(n, result) 5351556Srgrimes union node *n; 5361556Srgrimes struct backcmd *result; 53717987Speter{ 5381556Srgrimes int pip[2]; 5391556Srgrimes struct job *jp; 5401556Srgrimes struct stackmark smark; /* unnecessary */ 5411556Srgrimes 5421556Srgrimes setstackmark(&smark); 5431556Srgrimes result->fd = -1; 5441556Srgrimes result->buf = NULL; 5451556Srgrimes result->nleft = 0; 5461556Srgrimes result->jp = NULL; 54717987Speter if (n == NULL) { 54817987Speter exitstatus = 0; 5491556Srgrimes goto out; 55017987Speter } 5511556Srgrimes if (n->type == NCMD) { 55217987Speter exitstatus = oexitstatus; 5531556Srgrimes evalcommand(n, EV_BACKCMD, result); 5541556Srgrimes } else { 55517987Speter exitstatus = 0; 5561556Srgrimes if (pipe(pip) < 0) 5571556Srgrimes error("Pipe call failed"); 5581556Srgrimes jp = makejob(n, 1); 5591556Srgrimes if (forkshell(jp, n, FORK_NOJOB) == 0) { 5601556Srgrimes FORCEINTON; 5611556Srgrimes close(pip[0]); 5621556Srgrimes if (pip[1] != 1) { 5631556Srgrimes close(1); 5641556Srgrimes copyfd(pip[1], 1); 5651556Srgrimes close(pip[1]); 5661556Srgrimes } 5671556Srgrimes evaltree(n, EV_EXIT); 5681556Srgrimes } 5691556Srgrimes close(pip[1]); 5701556Srgrimes result->fd = pip[0]; 5711556Srgrimes result->jp = jp; 5721556Srgrimes } 5731556Srgrimesout: 5741556Srgrimes popstackmark(&smark); 5751556Srgrimes TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n", 5761556Srgrimes result->fd, result->buf, result->nleft, result->jp)); 5771556Srgrimes} 5781556Srgrimes 5791556Srgrimes 5801556Srgrimes 5811556Srgrimes/* 5821556Srgrimes * Execute a simple command. 5831556Srgrimes */ 5841556Srgrimes 5851556SrgrimesSTATIC void 5861556Srgrimesevalcommand(cmd, flags, backcmd) 5871556Srgrimes union node *cmd; 58817987Speter int flags; 5891556Srgrimes struct backcmd *backcmd; 59017987Speter{ 5911556Srgrimes struct stackmark smark; 5921556Srgrimes union node *argp; 5931556Srgrimes struct arglist arglist; 5941556Srgrimes struct arglist varlist; 5951556Srgrimes char **argv; 5961556Srgrimes int argc; 5971556Srgrimes char **envp; 5981556Srgrimes int varflag; 5991556Srgrimes struct strlist *sp; 6001556Srgrimes int mode; 6011556Srgrimes int pip[2]; 6021556Srgrimes struct cmdentry cmdentry; 6031556Srgrimes struct job *jp; 6041556Srgrimes struct jmploc jmploc; 6051556Srgrimes struct jmploc *volatile savehandler; 6061556Srgrimes char *volatile savecmdname; 6071556Srgrimes volatile struct shparam saveparam; 6081556Srgrimes struct localvar *volatile savelocalvars; 6091556Srgrimes volatile int e; 6101556Srgrimes char *lastarg; 61117987Speter#if __GNUC__ 61217987Speter /* Avoid longjmp clobbering */ 61317987Speter (void) &argv; 61417987Speter (void) &argc; 61517987Speter (void) &lastarg; 61617987Speter (void) &flags; 61717987Speter#endif 6181556Srgrimes 6191556Srgrimes /* First expand the arguments. */ 62017987Speter TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags)); 6211556Srgrimes setstackmark(&smark); 6221556Srgrimes arglist.lastp = &arglist.list; 6231556Srgrimes varlist.lastp = &varlist.list; 6241556Srgrimes varflag = 1; 62517987Speter oexitstatus = exitstatus; 62617987Speter exitstatus = 0; 6271556Srgrimes for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 62817987Speter char *p = argp->narg.text; 6291556Srgrimes if (varflag && is_name(*p)) { 6301556Srgrimes do { 6311556Srgrimes p++; 6321556Srgrimes } while (is_in_name(*p)); 6331556Srgrimes if (*p == '=') { 6341556Srgrimes expandarg(argp, &varlist, EXP_VARTILDE); 6351556Srgrimes continue; 6361556Srgrimes } 6371556Srgrimes } 6381556Srgrimes expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 6391556Srgrimes varflag = 0; 6401556Srgrimes } 6411556Srgrimes *arglist.lastp = NULL; 6421556Srgrimes *varlist.lastp = NULL; 6431556Srgrimes expredir(cmd->ncmd.redirect); 6441556Srgrimes argc = 0; 6451556Srgrimes for (sp = arglist.list ; sp ; sp = sp->next) 6461556Srgrimes argc++; 6471556Srgrimes argv = stalloc(sizeof (char *) * (argc + 1)); 6481556Srgrimes 6491556Srgrimes for (sp = arglist.list ; sp ; sp = sp->next) { 6501556Srgrimes TRACE(("evalcommand arg: %s\n", sp->text)); 6511556Srgrimes *argv++ = sp->text; 6521556Srgrimes } 6531556Srgrimes *argv = NULL; 6541556Srgrimes lastarg = NULL; 6551556Srgrimes if (iflag && funcnest == 0 && argc > 0) 6561556Srgrimes lastarg = argv[-1]; 6571556Srgrimes argv -= argc; 6581556Srgrimes 6591556Srgrimes /* Print the command if xflag is set. */ 6601556Srgrimes if (xflag) { 6611556Srgrimes outc('+', &errout); 6621556Srgrimes for (sp = varlist.list ; sp ; sp = sp->next) { 6631556Srgrimes outc(' ', &errout); 6641556Srgrimes out2str(sp->text); 6651556Srgrimes } 6661556Srgrimes for (sp = arglist.list ; sp ; sp = sp->next) { 6671556Srgrimes outc(' ', &errout); 6681556Srgrimes out2str(sp->text); 6691556Srgrimes } 6701556Srgrimes outc('\n', &errout); 6711556Srgrimes flushout(&errout); 6721556Srgrimes } 6731556Srgrimes 6741556Srgrimes /* Now locate the command. */ 6751556Srgrimes if (argc == 0) { 6761556Srgrimes cmdentry.cmdtype = CMDBUILTIN; 6771556Srgrimes cmdentry.u.index = BLTINCMD; 6781556Srgrimes } else { 67917987Speter static const char PATH[] = "PATH="; 68017987Speter char *path = pathval(); 68117987Speter 68217987Speter /* 68317987Speter * Modify the command lookup path, if a PATH= assignment 68417987Speter * is present 68517987Speter */ 68617987Speter for (sp = varlist.list ; sp ; sp = sp->next) 68717987Speter if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) 68817987Speter path = sp->text + sizeof(PATH) - 1; 68917987Speter 69017987Speter find_command(argv[0], &cmdentry, 1, path); 6911556Srgrimes if (cmdentry.cmdtype == CMDUNKNOWN) { /* command not found */ 69217987Speter exitstatus = 1; 6931556Srgrimes flushout(&errout); 6941556Srgrimes return; 6951556Srgrimes } 6961556Srgrimes /* implement the bltin builtin here */ 6971556Srgrimes if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == BLTINCMD) { 6981556Srgrimes for (;;) { 6991556Srgrimes argv++; 7001556Srgrimes if (--argc == 0) 7011556Srgrimes break; 7021556Srgrimes if ((cmdentry.u.index = find_builtin(*argv)) < 0) { 7031556Srgrimes outfmt(&errout, "%s: not found\n", *argv); 70417987Speter exitstatus = 1; 7051556Srgrimes flushout(&errout); 7061556Srgrimes return; 7071556Srgrimes } 7081556Srgrimes if (cmdentry.u.index != BLTINCMD) 7091556Srgrimes break; 7101556Srgrimes } 7111556Srgrimes } 7121556Srgrimes } 7131556Srgrimes 7141556Srgrimes /* Fork off a child process if necessary. */ 7151556Srgrimes if (cmd->ncmd.backgnd 71617987Speter || (cmdentry.cmdtype == CMDNORMAL && (flags & EV_EXIT) == 0) 71717987Speter || ((flags & EV_BACKCMD) != 0 7181556Srgrimes && (cmdentry.cmdtype != CMDBUILTIN 7191556Srgrimes || cmdentry.u.index == DOTCMD 72017987Speter || cmdentry.u.index == EVALCMD))) { 7211556Srgrimes jp = makejob(cmd, 1); 7221556Srgrimes mode = cmd->ncmd.backgnd; 7231556Srgrimes if (flags & EV_BACKCMD) { 7241556Srgrimes mode = FORK_NOJOB; 7251556Srgrimes if (pipe(pip) < 0) 7261556Srgrimes error("Pipe call failed"); 7271556Srgrimes } 7281556Srgrimes if (forkshell(jp, cmd, mode) != 0) 7291556Srgrimes goto parent; /* at end of routine */ 7301556Srgrimes if (flags & EV_BACKCMD) { 7311556Srgrimes FORCEINTON; 7321556Srgrimes close(pip[0]); 7331556Srgrimes if (pip[1] != 1) { 7341556Srgrimes close(1); 7351556Srgrimes copyfd(pip[1], 1); 7361556Srgrimes close(pip[1]); 7371556Srgrimes } 7381556Srgrimes } 7391556Srgrimes flags |= EV_EXIT; 7401556Srgrimes } 7411556Srgrimes 7421556Srgrimes /* This is the child process if a fork occurred. */ 7431556Srgrimes /* Execute the command. */ 7441556Srgrimes if (cmdentry.cmdtype == CMDFUNCTION) { 7451556Srgrimes trputs("Shell function: "); trargs(argv); 7461556Srgrimes redirect(cmd->ncmd.redirect, REDIR_PUSH); 7471556Srgrimes saveparam = shellparam; 7481556Srgrimes shellparam.malloc = 0; 7491556Srgrimes shellparam.nparam = argc - 1; 7501556Srgrimes shellparam.p = argv + 1; 7511556Srgrimes shellparam.optnext = NULL; 7521556Srgrimes INTOFF; 7531556Srgrimes savelocalvars = localvars; 7541556Srgrimes localvars = NULL; 7551556Srgrimes INTON; 7561556Srgrimes if (setjmp(jmploc.loc)) { 7571556Srgrimes if (exception == EXSHELLPROC) 7581556Srgrimes freeparam((struct shparam *)&saveparam); 7591556Srgrimes else { 7601556Srgrimes freeparam(&shellparam); 7611556Srgrimes shellparam = saveparam; 7621556Srgrimes } 7631556Srgrimes poplocalvars(); 7641556Srgrimes localvars = savelocalvars; 7651556Srgrimes handler = savehandler; 7661556Srgrimes longjmp(handler->loc, 1); 7671556Srgrimes } 7681556Srgrimes savehandler = handler; 7691556Srgrimes handler = &jmploc; 7701556Srgrimes for (sp = varlist.list ; sp ; sp = sp->next) 7711556Srgrimes mklocal(sp->text); 7721556Srgrimes funcnest++; 7731556Srgrimes evaltree(cmdentry.u.func, 0); 7741556Srgrimes funcnest--; 7751556Srgrimes INTOFF; 7761556Srgrimes poplocalvars(); 7771556Srgrimes localvars = savelocalvars; 7781556Srgrimes freeparam(&shellparam); 7791556Srgrimes shellparam = saveparam; 7801556Srgrimes handler = savehandler; 7811556Srgrimes popredir(); 7821556Srgrimes INTON; 7831556Srgrimes if (evalskip == SKIPFUNC) { 7841556Srgrimes evalskip = 0; 7851556Srgrimes skipcount = 0; 7861556Srgrimes } 7871556Srgrimes if (flags & EV_EXIT) 7881556Srgrimes exitshell(exitstatus); 7891556Srgrimes } else if (cmdentry.cmdtype == CMDBUILTIN) { 7901556Srgrimes trputs("builtin command: "); trargs(argv); 7911556Srgrimes mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; 7921556Srgrimes if (flags == EV_BACKCMD) { 7931556Srgrimes memout.nleft = 0; 7941556Srgrimes memout.nextc = memout.buf; 7951556Srgrimes memout.bufsize = 64; 7961556Srgrimes mode |= REDIR_BACKQ; 7971556Srgrimes } 7981556Srgrimes redirect(cmd->ncmd.redirect, mode); 7991556Srgrimes savecmdname = commandname; 8001556Srgrimes cmdenviron = varlist.list; 8011556Srgrimes e = -1; 8021556Srgrimes if (setjmp(jmploc.loc)) { 8031556Srgrimes e = exception; 8041556Srgrimes exitstatus = (e == EXINT)? SIGINT+128 : 2; 8051556Srgrimes goto cmddone; 8061556Srgrimes } 8071556Srgrimes savehandler = handler; 8081556Srgrimes handler = &jmploc; 8091556Srgrimes commandname = argv[0]; 8101556Srgrimes argptr = argv + 1; 8111556Srgrimes optptr = NULL; /* initialize nextopt */ 8121556Srgrimes exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); 8131556Srgrimes flushall(); 8141556Srgrimescmddone: 8151556Srgrimes out1 = &output; 8161556Srgrimes out2 = &errout; 8171556Srgrimes freestdout(); 8181556Srgrimes if (e != EXSHELLPROC) { 8191556Srgrimes commandname = savecmdname; 8201556Srgrimes if (flags & EV_EXIT) { 8211556Srgrimes exitshell(exitstatus); 8221556Srgrimes } 8231556Srgrimes } 8241556Srgrimes handler = savehandler; 8251556Srgrimes if (e != -1) { 8261556Srgrimes if (e != EXERROR || cmdentry.u.index == BLTINCMD 8271556Srgrimes || cmdentry.u.index == DOTCMD 8281556Srgrimes || cmdentry.u.index == EVALCMD 82917987Speter#ifndef NO_HISTORY 8301556Srgrimes || cmdentry.u.index == HISTCMD 83117987Speter#endif 8321556Srgrimes || cmdentry.u.index == EXECCMD) 8331556Srgrimes exraise(e); 8341556Srgrimes FORCEINTON; 8351556Srgrimes } 8361556Srgrimes if (cmdentry.u.index != EXECCMD) 8371556Srgrimes popredir(); 8381556Srgrimes if (flags == EV_BACKCMD) { 8391556Srgrimes backcmd->buf = memout.buf; 8401556Srgrimes backcmd->nleft = memout.nextc - memout.buf; 8411556Srgrimes memout.buf = NULL; 8421556Srgrimes } 8431556Srgrimes } else { 8441556Srgrimes trputs("normal command: "); trargs(argv); 8451556Srgrimes clearredir(); 8461556Srgrimes redirect(cmd->ncmd.redirect, 0); 8471556Srgrimes for (sp = varlist.list ; sp ; sp = sp->next) 8481556Srgrimes setvareq(sp->text, VEXPORT|VSTACK); 8491556Srgrimes envp = environment(); 85017987Speter shellexec(argv, envp, pathval(), cmdentry.u.index); 8511556Srgrimes /*NOTREACHED*/ 8521556Srgrimes } 8531556Srgrimes goto out; 8541556Srgrimes 8551556Srgrimesparent: /* parent process gets here (if we forked) */ 8561556Srgrimes if (mode == 0) { /* argument to fork */ 8571556Srgrimes INTOFF; 8581556Srgrimes exitstatus = waitforjob(jp); 8591556Srgrimes INTON; 8601556Srgrimes } else if (mode == 2) { 8611556Srgrimes backcmd->fd = pip[0]; 8621556Srgrimes close(pip[1]); 8631556Srgrimes backcmd->jp = jp; 8641556Srgrimes } 8651556Srgrimes 8661556Srgrimesout: 8671556Srgrimes if (lastarg) 8681556Srgrimes setvar("_", lastarg, 0); 8691556Srgrimes popstackmark(&smark); 8701556Srgrimes} 8711556Srgrimes 8721556Srgrimes 8731556Srgrimes 8741556Srgrimes/* 8751556Srgrimes * Search for a command. This is called before we fork so that the 8761556Srgrimes * location of the command will be available in the parent as well as 8771556Srgrimes * the child. The check for "goodname" is an overly conservative 8781556Srgrimes * check that the name will not be subject to expansion. 8791556Srgrimes */ 8801556Srgrimes 8811556SrgrimesSTATIC void 8821556Srgrimesprehash(n) 8831556Srgrimes union node *n; 88417987Speter{ 8851556Srgrimes struct cmdentry entry; 8861556Srgrimes 88717987Speter if (n->type == NCMD && n->ncmd.args) 88817987Speter if (goodname(n->ncmd.args->narg.text)) 88917987Speter find_command(n->ncmd.args->narg.text, &entry, 0, 89017987Speter pathval()); 8911556Srgrimes} 8921556Srgrimes 8931556Srgrimes 8941556Srgrimes 8951556Srgrimes/* 8961556Srgrimes * Builtin commands. Builtin commands whose functions are closely 8971556Srgrimes * tied to evaluation are implemented here. 8981556Srgrimes */ 8991556Srgrimes 9001556Srgrimes/* 9011556Srgrimes * No command given, or a bltin command with no arguments. Set the 9021556Srgrimes * specified variables. 9031556Srgrimes */ 9041556Srgrimes 90517987Speterint 90617987Speterbltincmd(argc, argv) 90717987Speter int argc; 90817987Speter char **argv; 90917987Speter{ 9101556Srgrimes listsetvar(cmdenviron); 91117987Speter /* 91217987Speter * Preserve exitstatus of a previous possible redirection 91317987Speter * as POSIX mandates 91417987Speter */ 9151556Srgrimes return exitstatus; 9161556Srgrimes} 9171556Srgrimes 9181556Srgrimes 9191556Srgrimes/* 9201556Srgrimes * Handle break and continue commands. Break, continue, and return are 9211556Srgrimes * all handled by setting the evalskip flag. The evaluation routines 9221556Srgrimes * above all check this flag, and if it is set they start skipping 9231556Srgrimes * commands rather than executing them. The variable skipcount is 9241556Srgrimes * the number of loops to break/continue, or the number of function 9251556Srgrimes * levels to return. (The latter is always 1.) It should probably 9261556Srgrimes * be an error to break out of more loops than exist, but it isn't 9271556Srgrimes * in the standard shell so we don't make it one here. 9281556Srgrimes */ 9291556Srgrimes 93017987Speterint 93117987Speterbreakcmd(argc, argv) 93217987Speter int argc; 93317987Speter char **argv; 93417987Speter{ 9351556Srgrimes int n; 9361556Srgrimes 9371556Srgrimes n = 1; 9381556Srgrimes if (argc > 1) 9391556Srgrimes n = number(argv[1]); 9401556Srgrimes if (n > loopnest) 9411556Srgrimes n = loopnest; 9421556Srgrimes if (n > 0) { 9431556Srgrimes evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 9441556Srgrimes skipcount = n; 9451556Srgrimes } 9461556Srgrimes return 0; 9471556Srgrimes} 9481556Srgrimes 9491556Srgrimes 9501556Srgrimes/* 9511556Srgrimes * The return command. 9521556Srgrimes */ 9531556Srgrimes 95417987Speterint 95517987Speterreturncmd(argc, argv) 95617987Speter int argc; 95717987Speter char **argv; 95817987Speter{ 9591556Srgrimes int ret; 9601556Srgrimes 9611556Srgrimes ret = exitstatus; 9621556Srgrimes if (argc > 1) 9631556Srgrimes ret = number(argv[1]); 9641556Srgrimes if (funcnest) { 9651556Srgrimes evalskip = SKIPFUNC; 9661556Srgrimes skipcount = 1; 9671556Srgrimes } 9681556Srgrimes return ret; 9691556Srgrimes} 9701556Srgrimes 9711556Srgrimes 97217987Speterint 97317987Speterfalsecmd(argc, argv) 97417987Speter int argc; 97517987Speter char **argv; 97617987Speter{ 97717987Speter return 1; 97817987Speter} 97917987Speter 98017987Speter 98117987Speterint 98217987Spetertruecmd(argc, argv) 98317987Speter int argc; 98417987Speter char **argv; 98517987Speter{ 9861556Srgrimes return 0; 9871556Srgrimes} 9881556Srgrimes 9891556Srgrimes 99017987Speterint 99117987Speterexeccmd(argc, argv) 99217987Speter int argc; 99317987Speter char **argv; 99417987Speter{ 9951556Srgrimes if (argc > 1) { 99617987Speter struct strlist *sp; 99717987Speter 9981556Srgrimes iflag = 0; /* exit on error */ 9991556Srgrimes mflag = 0; 10001556Srgrimes optschanged(); 100117987Speter for (sp = cmdenviron; sp ; sp = sp->next) 100217987Speter setvareq(sp->text, VEXPORT|VSTACK); 10031556Srgrimes shellexec(argv + 1, environment(), pathval(), 0); 10041556Srgrimes 10051556Srgrimes } 10061556Srgrimes return 0; 10071556Srgrimes} 1008