eval.c revision 20425
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 * 3620425Ssteve * $Id: eval.c,v 1.8 1996/11/12 18:35:06 peter Exp $ 371556Srgrimes */ 381556Srgrimes 391556Srgrimes#ifndef lint 4020425Sstevestatic char const 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 791556SrgrimesMKINIT int evalskip; /* set if we are skipping commands */ 801556SrgrimesSTATIC int skipcount; /* number of levels to skip */ 811556SrgrimesMKINIT int loopnest; /* current loop nesting level */ 821556Srgrimesint funcnest; /* depth of function calls */ 831556Srgrimes 841556Srgrimes 851556Srgrimeschar *commandname; 861556Srgrimesstruct strlist *cmdenviron; 871556Srgrimesint exitstatus; /* exit status of last command */ 8817987Speterint oexitstatus; /* saved exit status */ 891556Srgrimes 901556Srgrimes 9117987SpeterSTATIC void evalloop __P((union node *)); 9217987SpeterSTATIC void evalfor __P((union node *)); 9317987SpeterSTATIC void evalcase __P((union node *, int)); 9417987SpeterSTATIC void evalsubshell __P((union node *, int)); 9517987SpeterSTATIC void expredir __P((union node *)); 9617987SpeterSTATIC void evalpipe __P((union node *)); 9717987SpeterSTATIC void evalcommand __P((union node *, int, struct backcmd *)); 9817987SpeterSTATIC void prehash __P((union node *)); 991556Srgrimes 1001556Srgrimes 1011556Srgrimes/* 1021556Srgrimes * Called to reset things after an exception. 1031556Srgrimes */ 1041556Srgrimes 1051556Srgrimes#ifdef mkinit 1061556SrgrimesINCLUDE "eval.h" 1071556Srgrimes 1081556SrgrimesRESET { 1091556Srgrimes evalskip = 0; 1101556Srgrimes loopnest = 0; 1111556Srgrimes funcnest = 0; 1121556Srgrimes} 1131556Srgrimes 1141556SrgrimesSHELLPROC { 1151556Srgrimes exitstatus = 0; 1161556Srgrimes} 1171556Srgrimes#endif 1181556Srgrimes 1191556Srgrimes 1201556Srgrimes 1211556Srgrimes/* 1221556Srgrimes * The eval commmand. 1231556Srgrimes */ 1241556Srgrimes 12517987Speterint 12620425Ssteveevalcmd(argc, argv) 12717987Speter int argc; 12820425Ssteve char **argv; 1291556Srgrimes{ 1301556Srgrimes char *p; 1311556Srgrimes char *concat; 1321556Srgrimes char **ap; 1331556Srgrimes 1341556Srgrimes if (argc > 1) { 1351556Srgrimes p = argv[1]; 1361556Srgrimes if (argc > 2) { 1371556Srgrimes STARTSTACKSTR(concat); 1381556Srgrimes ap = argv + 2; 1391556Srgrimes for (;;) { 1401556Srgrimes while (*p) 1411556Srgrimes STPUTC(*p++, concat); 1421556Srgrimes if ((p = *ap++) == NULL) 1431556Srgrimes break; 1441556Srgrimes STPUTC(' ', concat); 1451556Srgrimes } 1461556Srgrimes STPUTC('\0', concat); 1471556Srgrimes p = grabstackstr(concat); 1481556Srgrimes } 1491556Srgrimes evalstring(p); 1501556Srgrimes } 1511556Srgrimes return exitstatus; 1521556Srgrimes} 1531556Srgrimes 1541556Srgrimes 1551556Srgrimes/* 1561556Srgrimes * Execute a command or commands contained in a string. 1571556Srgrimes */ 1581556Srgrimes 1591556Srgrimesvoid 1601556Srgrimesevalstring(s) 1611556Srgrimes char *s; 1621556Srgrimes { 1631556Srgrimes union node *n; 1641556Srgrimes struct stackmark smark; 1651556Srgrimes 1661556Srgrimes setstackmark(&smark); 1671556Srgrimes setinputstring(s, 1); 1681556Srgrimes while ((n = parsecmd(0)) != NEOF) { 1691556Srgrimes evaltree(n, 0); 1701556Srgrimes popstackmark(&smark); 1711556Srgrimes } 1721556Srgrimes popfile(); 1731556Srgrimes popstackmark(&smark); 1741556Srgrimes} 1751556Srgrimes 1761556Srgrimes 1771556Srgrimes 1781556Srgrimes/* 1791556Srgrimes * Evaluate a parse tree. The value is left in the global variable 1801556Srgrimes * exitstatus. 1811556Srgrimes */ 1821556Srgrimes 1831556Srgrimesvoid 1841556Srgrimesevaltree(n, flags) 1851556Srgrimes union node *n; 18617987Speter int flags; 18717987Speter{ 1881556Srgrimes if (n == NULL) { 1891556Srgrimes TRACE(("evaltree(NULL) called\n")); 1901556Srgrimes exitstatus = 0; 1911556Srgrimes goto out; 1921556Srgrimes } 19317987Speter#ifndef NO_HISTORY 1941556Srgrimes displayhist = 1; /* show history substitutions done with fc */ 19517987Speter#endif 19617987Speter TRACE(("evaltree(0x%lx: %d) called\n", (long)n, n->type)); 1971556Srgrimes switch (n->type) { 1981556Srgrimes case NSEMI: 1991556Srgrimes evaltree(n->nbinary.ch1, 0); 2001556Srgrimes if (evalskip) 2011556Srgrimes goto out; 2021556Srgrimes evaltree(n->nbinary.ch2, flags); 2031556Srgrimes break; 2041556Srgrimes case NAND: 2051556Srgrimes evaltree(n->nbinary.ch1, EV_TESTED); 20618754Ssteve if (evalskip || exitstatus != 0) { 20718754Ssteve flags |= EV_TESTED; 2081556Srgrimes goto out; 20918754Ssteve } 2101556Srgrimes evaltree(n->nbinary.ch2, flags); 2111556Srgrimes break; 2121556Srgrimes case NOR: 2131556Srgrimes evaltree(n->nbinary.ch1, EV_TESTED); 2141556Srgrimes if (evalskip || exitstatus == 0) 2151556Srgrimes goto out; 2161556Srgrimes evaltree(n->nbinary.ch2, flags); 2171556Srgrimes break; 2181556Srgrimes case NREDIR: 2191556Srgrimes expredir(n->nredir.redirect); 2201556Srgrimes redirect(n->nredir.redirect, REDIR_PUSH); 2211556Srgrimes evaltree(n->nredir.n, flags); 2221556Srgrimes popredir(); 2231556Srgrimes break; 2241556Srgrimes case NSUBSHELL: 2251556Srgrimes evalsubshell(n, flags); 2261556Srgrimes break; 2271556Srgrimes case NBACKGND: 2281556Srgrimes evalsubshell(n, flags); 2291556Srgrimes break; 2301556Srgrimes case NIF: { 2311556Srgrimes evaltree(n->nif.test, EV_TESTED); 2321556Srgrimes if (evalskip) 2331556Srgrimes goto out; 23420425Ssteve if (exitstatus == 0) 2351556Srgrimes evaltree(n->nif.ifpart, flags); 23617987Speter else if (n->nif.elsepart) 2371556Srgrimes evaltree(n->nif.elsepart, flags); 23820425Ssteve else 23920425Ssteve exitstatus = 0; 2401556Srgrimes break; 2411556Srgrimes } 2421556Srgrimes case NWHILE: 2431556Srgrimes case NUNTIL: 2441556Srgrimes evalloop(n); 2451556Srgrimes break; 2461556Srgrimes case NFOR: 2471556Srgrimes evalfor(n); 2481556Srgrimes break; 2491556Srgrimes case NCASE: 2501556Srgrimes evalcase(n, flags); 2511556Srgrimes break; 2521556Srgrimes case NDEFUN: 2531556Srgrimes defun(n->narg.text, n->narg.next); 2541556Srgrimes exitstatus = 0; 2551556Srgrimes break; 2561556Srgrimes case NNOT: 2571556Srgrimes evaltree(n->nnot.com, EV_TESTED); 2581556Srgrimes exitstatus = !exitstatus; 2591556Srgrimes break; 2601556Srgrimes 2611556Srgrimes case NPIPE: 2621556Srgrimes evalpipe(n); 2631556Srgrimes break; 2641556Srgrimes case NCMD: 2651556Srgrimes evalcommand(n, flags, (struct backcmd *)NULL); 2661556Srgrimes break; 2671556Srgrimes default: 2681556Srgrimes out1fmt("Node type = %d\n", n->type); 2691556Srgrimes flushout(&output); 2701556Srgrimes break; 2711556Srgrimes } 2721556Srgrimesout: 2731556Srgrimes if (pendingsigs) 2741556Srgrimes dotrap(); 2751556Srgrimes if ((flags & EV_EXIT) || (eflag && exitstatus && !(flags & EV_TESTED))) 2761556Srgrimes exitshell(exitstatus); 2771556Srgrimes} 2781556Srgrimes 2791556Srgrimes 2801556SrgrimesSTATIC void 2811556Srgrimesevalloop(n) 2821556Srgrimes union node *n; 28317987Speter{ 2841556Srgrimes int status; 2851556Srgrimes 2861556Srgrimes loopnest++; 2871556Srgrimes status = 0; 2881556Srgrimes for (;;) { 2891556Srgrimes evaltree(n->nbinary.ch1, EV_TESTED); 2901556Srgrimes if (evalskip) { 2911556Srgrimesskipping: if (evalskip == SKIPCONT && --skipcount <= 0) { 2921556Srgrimes evalskip = 0; 2931556Srgrimes continue; 2941556Srgrimes } 2951556Srgrimes if (evalskip == SKIPBREAK && --skipcount <= 0) 2961556Srgrimes evalskip = 0; 2971556Srgrimes break; 2981556Srgrimes } 2991556Srgrimes if (n->type == NWHILE) { 3001556Srgrimes if (exitstatus != 0) 3011556Srgrimes break; 3021556Srgrimes } else { 3031556Srgrimes if (exitstatus == 0) 3041556Srgrimes break; 3051556Srgrimes } 3061556Srgrimes evaltree(n->nbinary.ch2, 0); 3071556Srgrimes status = exitstatus; 3081556Srgrimes if (evalskip) 3091556Srgrimes goto skipping; 3101556Srgrimes } 3111556Srgrimes loopnest--; 3121556Srgrimes exitstatus = status; 3131556Srgrimes} 3141556Srgrimes 3151556Srgrimes 3161556Srgrimes 3171556SrgrimesSTATIC void 3181556Srgrimesevalfor(n) 31917987Speter union node *n; 32017987Speter{ 3211556Srgrimes struct arglist arglist; 3221556Srgrimes union node *argp; 3231556Srgrimes struct strlist *sp; 3241556Srgrimes struct stackmark smark; 3251556Srgrimes 3261556Srgrimes setstackmark(&smark); 3271556Srgrimes arglist.lastp = &arglist.list; 3281556Srgrimes for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { 32917987Speter oexitstatus = exitstatus; 3301556Srgrimes expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 3311556Srgrimes if (evalskip) 3321556Srgrimes goto out; 3331556Srgrimes } 3341556Srgrimes *arglist.lastp = NULL; 3351556Srgrimes 3361556Srgrimes exitstatus = 0; 3371556Srgrimes loopnest++; 3381556Srgrimes for (sp = arglist.list ; sp ; sp = sp->next) { 3391556Srgrimes setvar(n->nfor.var, sp->text, 0); 3401556Srgrimes evaltree(n->nfor.body, 0); 3411556Srgrimes if (evalskip) { 3421556Srgrimes if (evalskip == SKIPCONT && --skipcount <= 0) { 3431556Srgrimes evalskip = 0; 3441556Srgrimes continue; 3451556Srgrimes } 3461556Srgrimes if (evalskip == SKIPBREAK && --skipcount <= 0) 3471556Srgrimes evalskip = 0; 3481556Srgrimes break; 3491556Srgrimes } 3501556Srgrimes } 3511556Srgrimes loopnest--; 3521556Srgrimesout: 3531556Srgrimes popstackmark(&smark); 3541556Srgrimes} 3551556Srgrimes 3561556Srgrimes 3571556Srgrimes 3581556SrgrimesSTATIC void 3591556Srgrimesevalcase(n, flags) 3601556Srgrimes union node *n; 36117987Speter int flags; 36217987Speter{ 3631556Srgrimes union node *cp; 3641556Srgrimes union node *patp; 3651556Srgrimes struct arglist arglist; 3661556Srgrimes struct stackmark smark; 3671556Srgrimes 3681556Srgrimes setstackmark(&smark); 3691556Srgrimes arglist.lastp = &arglist.list; 37017987Speter oexitstatus = exitstatus; 3711556Srgrimes expandarg(n->ncase.expr, &arglist, EXP_TILDE); 3721556Srgrimes for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) { 3731556Srgrimes for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { 3741556Srgrimes if (casematch(patp, arglist.list->text)) { 3751556Srgrimes if (evalskip == 0) { 3761556Srgrimes evaltree(cp->nclist.body, flags); 3771556Srgrimes } 3781556Srgrimes goto out; 3791556Srgrimes } 3801556Srgrimes } 3811556Srgrimes } 3821556Srgrimesout: 3831556Srgrimes popstackmark(&smark); 3841556Srgrimes} 3851556Srgrimes 3861556Srgrimes 3871556Srgrimes 3881556Srgrimes/* 3891556Srgrimes * Kick off a subshell to evaluate a tree. 3901556Srgrimes */ 3911556Srgrimes 3921556SrgrimesSTATIC void 3931556Srgrimesevalsubshell(n, flags) 3941556Srgrimes union node *n; 39517987Speter int flags; 39617987Speter{ 3971556Srgrimes struct job *jp; 3981556Srgrimes int backgnd = (n->type == NBACKGND); 3991556Srgrimes 4001556Srgrimes expredir(n->nredir.redirect); 4011556Srgrimes jp = makejob(n, 1); 4021556Srgrimes if (forkshell(jp, n, backgnd) == 0) { 4031556Srgrimes if (backgnd) 4041556Srgrimes flags &=~ EV_TESTED; 4051556Srgrimes redirect(n->nredir.redirect, 0); 4061556Srgrimes evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ 4071556Srgrimes } 4081556Srgrimes if (! backgnd) { 4091556Srgrimes INTOFF; 4101556Srgrimes exitstatus = waitforjob(jp); 4111556Srgrimes INTON; 4121556Srgrimes } 4131556Srgrimes} 4141556Srgrimes 4151556Srgrimes 4161556Srgrimes 4171556Srgrimes/* 4181556Srgrimes * Compute the names of the files in a redirection list. 4191556Srgrimes */ 4201556Srgrimes 4211556SrgrimesSTATIC void 4221556Srgrimesexpredir(n) 4231556Srgrimes union node *n; 42417987Speter{ 4251556Srgrimes register union node *redir; 4261556Srgrimes 4271556Srgrimes for (redir = n ; redir ; redir = redir->nfile.next) { 42817987Speter struct arglist fn; 42917987Speter fn.lastp = &fn.list; 43017987Speter oexitstatus = exitstatus; 43117987Speter switch (redir->type) { 43217987Speter case NFROM: 43317987Speter case NTO: 43417987Speter case NAPPEND: 4351556Srgrimes expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); 4361556Srgrimes redir->nfile.expfname = fn.list->text; 43717987Speter break; 43817987Speter case NFROMFD: 43917987Speter case NTOFD: 44017987Speter if (redir->ndup.vname) { 44117987Speter expandarg(redir->ndup.vname, &fn, EXP_FULL | EXP_TILDE); 44217987Speter fixredir(redir, fn.list->text, 1); 44317987Speter } 44417987Speter break; 4451556Srgrimes } 4461556Srgrimes } 4471556Srgrimes} 4481556Srgrimes 4491556Srgrimes 4501556Srgrimes 4511556Srgrimes/* 4521556Srgrimes * Evaluate a pipeline. All the processes in the pipeline are children 4531556Srgrimes * of the process creating the pipeline. (This differs from some versions 4541556Srgrimes * of the shell, which make the last process in a pipeline the parent 4551556Srgrimes * of all the rest.) 4561556Srgrimes */ 4571556Srgrimes 4581556SrgrimesSTATIC void 4591556Srgrimesevalpipe(n) 4601556Srgrimes union node *n; 46117987Speter{ 4621556Srgrimes struct job *jp; 4631556Srgrimes struct nodelist *lp; 4641556Srgrimes int pipelen; 4651556Srgrimes int prevfd; 4661556Srgrimes int pip[2]; 4671556Srgrimes 46817987Speter TRACE(("evalpipe(0x%lx) called\n", (long)n)); 4691556Srgrimes pipelen = 0; 4701556Srgrimes for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) 4711556Srgrimes pipelen++; 4721556Srgrimes INTOFF; 4731556Srgrimes jp = makejob(n, pipelen); 4741556Srgrimes prevfd = -1; 4751556Srgrimes for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 4761556Srgrimes prehash(lp->n); 4771556Srgrimes pip[1] = -1; 4781556Srgrimes if (lp->next) { 4791556Srgrimes if (pipe(pip) < 0) { 4801556Srgrimes close(prevfd); 4811556Srgrimes error("Pipe call failed"); 4821556Srgrimes } 4831556Srgrimes } 4841556Srgrimes if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { 4851556Srgrimes INTON; 4861556Srgrimes if (prevfd > 0) { 4871556Srgrimes close(0); 4881556Srgrimes copyfd(prevfd, 0); 4891556Srgrimes close(prevfd); 4901556Srgrimes } 4911556Srgrimes if (pip[1] >= 0) { 4921556Srgrimes close(pip[0]); 4931556Srgrimes if (pip[1] != 1) { 4941556Srgrimes close(1); 4951556Srgrimes copyfd(pip[1], 1); 4961556Srgrimes close(pip[1]); 4971556Srgrimes } 4981556Srgrimes } 4991556Srgrimes evaltree(lp->n, EV_EXIT); 5001556Srgrimes } 5011556Srgrimes if (prevfd >= 0) 5021556Srgrimes close(prevfd); 5031556Srgrimes prevfd = pip[0]; 5041556Srgrimes close(pip[1]); 5051556Srgrimes } 5061556Srgrimes INTON; 5071556Srgrimes if (n->npipe.backgnd == 0) { 5081556Srgrimes INTOFF; 5091556Srgrimes exitstatus = waitforjob(jp); 5101556Srgrimes TRACE(("evalpipe: job done exit status %d\n", exitstatus)); 5111556Srgrimes INTON; 5121556Srgrimes } 5131556Srgrimes} 5141556Srgrimes 5151556Srgrimes 5161556Srgrimes 5171556Srgrimes/* 5181556Srgrimes * Execute a command inside back quotes. If it's a builtin command, we 5191556Srgrimes * want to save its output in a block obtained from malloc. Otherwise 5201556Srgrimes * we fork off a subprocess and get the output of the command via a pipe. 5211556Srgrimes * Should be called with interrupts off. 5221556Srgrimes */ 5231556Srgrimes 5241556Srgrimesvoid 5251556Srgrimesevalbackcmd(n, result) 5261556Srgrimes union node *n; 5271556Srgrimes struct backcmd *result; 52817987Speter{ 5291556Srgrimes int pip[2]; 5301556Srgrimes struct job *jp; 5311556Srgrimes struct stackmark smark; /* unnecessary */ 5321556Srgrimes 5331556Srgrimes setstackmark(&smark); 5341556Srgrimes result->fd = -1; 5351556Srgrimes result->buf = NULL; 5361556Srgrimes result->nleft = 0; 5371556Srgrimes result->jp = NULL; 53817987Speter if (n == NULL) { 53917987Speter exitstatus = 0; 5401556Srgrimes goto out; 54117987Speter } 5421556Srgrimes if (n->type == NCMD) { 54317987Speter exitstatus = oexitstatus; 5441556Srgrimes evalcommand(n, EV_BACKCMD, result); 5451556Srgrimes } else { 54617987Speter exitstatus = 0; 5471556Srgrimes if (pipe(pip) < 0) 5481556Srgrimes error("Pipe call failed"); 5491556Srgrimes jp = makejob(n, 1); 5501556Srgrimes if (forkshell(jp, n, FORK_NOJOB) == 0) { 5511556Srgrimes FORCEINTON; 5521556Srgrimes close(pip[0]); 5531556Srgrimes if (pip[1] != 1) { 5541556Srgrimes close(1); 5551556Srgrimes copyfd(pip[1], 1); 5561556Srgrimes close(pip[1]); 5571556Srgrimes } 5581556Srgrimes evaltree(n, EV_EXIT); 5591556Srgrimes } 5601556Srgrimes close(pip[1]); 5611556Srgrimes result->fd = pip[0]; 5621556Srgrimes result->jp = jp; 5631556Srgrimes } 5641556Srgrimesout: 5651556Srgrimes popstackmark(&smark); 5661556Srgrimes TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n", 5671556Srgrimes result->fd, result->buf, result->nleft, result->jp)); 5681556Srgrimes} 5691556Srgrimes 5701556Srgrimes 5711556Srgrimes 5721556Srgrimes/* 5731556Srgrimes * Execute a simple command. 5741556Srgrimes */ 5751556Srgrimes 5761556SrgrimesSTATIC void 5771556Srgrimesevalcommand(cmd, flags, backcmd) 5781556Srgrimes union node *cmd; 57917987Speter int flags; 5801556Srgrimes struct backcmd *backcmd; 58117987Speter{ 5821556Srgrimes struct stackmark smark; 5831556Srgrimes union node *argp; 5841556Srgrimes struct arglist arglist; 5851556Srgrimes struct arglist varlist; 5861556Srgrimes char **argv; 5871556Srgrimes int argc; 5881556Srgrimes char **envp; 5891556Srgrimes int varflag; 5901556Srgrimes struct strlist *sp; 5911556Srgrimes int mode; 5921556Srgrimes int pip[2]; 5931556Srgrimes struct cmdentry cmdentry; 5941556Srgrimes struct job *jp; 5951556Srgrimes struct jmploc jmploc; 5961556Srgrimes struct jmploc *volatile savehandler; 5971556Srgrimes char *volatile savecmdname; 5981556Srgrimes volatile struct shparam saveparam; 5991556Srgrimes struct localvar *volatile savelocalvars; 6001556Srgrimes volatile int e; 6011556Srgrimes char *lastarg; 60217987Speter#if __GNUC__ 60317987Speter /* Avoid longjmp clobbering */ 60417987Speter (void) &argv; 60517987Speter (void) &argc; 60617987Speter (void) &lastarg; 60717987Speter (void) &flags; 60817987Speter#endif 6091556Srgrimes 6101556Srgrimes /* First expand the arguments. */ 61117987Speter TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags)); 6121556Srgrimes setstackmark(&smark); 6131556Srgrimes arglist.lastp = &arglist.list; 6141556Srgrimes varlist.lastp = &varlist.list; 6151556Srgrimes varflag = 1; 61617987Speter oexitstatus = exitstatus; 61717987Speter exitstatus = 0; 6181556Srgrimes for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 61917987Speter char *p = argp->narg.text; 6201556Srgrimes if (varflag && is_name(*p)) { 6211556Srgrimes do { 6221556Srgrimes p++; 6231556Srgrimes } while (is_in_name(*p)); 6241556Srgrimes if (*p == '=') { 6251556Srgrimes expandarg(argp, &varlist, EXP_VARTILDE); 6261556Srgrimes continue; 6271556Srgrimes } 6281556Srgrimes } 6291556Srgrimes expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 6301556Srgrimes varflag = 0; 6311556Srgrimes } 6321556Srgrimes *arglist.lastp = NULL; 6331556Srgrimes *varlist.lastp = NULL; 6341556Srgrimes expredir(cmd->ncmd.redirect); 6351556Srgrimes argc = 0; 6361556Srgrimes for (sp = arglist.list ; sp ; sp = sp->next) 6371556Srgrimes argc++; 6381556Srgrimes argv = stalloc(sizeof (char *) * (argc + 1)); 6391556Srgrimes 6401556Srgrimes for (sp = arglist.list ; sp ; sp = sp->next) { 6411556Srgrimes TRACE(("evalcommand arg: %s\n", sp->text)); 6421556Srgrimes *argv++ = sp->text; 6431556Srgrimes } 6441556Srgrimes *argv = NULL; 6451556Srgrimes lastarg = NULL; 6461556Srgrimes if (iflag && funcnest == 0 && argc > 0) 6471556Srgrimes lastarg = argv[-1]; 6481556Srgrimes argv -= argc; 6491556Srgrimes 6501556Srgrimes /* Print the command if xflag is set. */ 6511556Srgrimes if (xflag) { 6521556Srgrimes outc('+', &errout); 6531556Srgrimes for (sp = varlist.list ; sp ; sp = sp->next) { 6541556Srgrimes outc(' ', &errout); 6551556Srgrimes out2str(sp->text); 6561556Srgrimes } 6571556Srgrimes for (sp = arglist.list ; sp ; sp = sp->next) { 6581556Srgrimes outc(' ', &errout); 6591556Srgrimes out2str(sp->text); 6601556Srgrimes } 6611556Srgrimes outc('\n', &errout); 6621556Srgrimes flushout(&errout); 6631556Srgrimes } 6641556Srgrimes 6651556Srgrimes /* Now locate the command. */ 6661556Srgrimes if (argc == 0) { 6671556Srgrimes cmdentry.cmdtype = CMDBUILTIN; 6681556Srgrimes cmdentry.u.index = BLTINCMD; 6691556Srgrimes } else { 67017987Speter static const char PATH[] = "PATH="; 67117987Speter char *path = pathval(); 67217987Speter 67317987Speter /* 67417987Speter * Modify the command lookup path, if a PATH= assignment 67517987Speter * is present 67617987Speter */ 67717987Speter for (sp = varlist.list ; sp ; sp = sp->next) 67817987Speter if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) 67917987Speter path = sp->text + sizeof(PATH) - 1; 68017987Speter 68117987Speter find_command(argv[0], &cmdentry, 1, path); 6821556Srgrimes if (cmdentry.cmdtype == CMDUNKNOWN) { /* command not found */ 68320425Ssteve exitstatus = 127; 6841556Srgrimes flushout(&errout); 6851556Srgrimes return; 6861556Srgrimes } 6871556Srgrimes /* implement the bltin builtin here */ 6881556Srgrimes if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == BLTINCMD) { 6891556Srgrimes for (;;) { 6901556Srgrimes argv++; 6911556Srgrimes if (--argc == 0) 6921556Srgrimes break; 6931556Srgrimes if ((cmdentry.u.index = find_builtin(*argv)) < 0) { 6941556Srgrimes outfmt(&errout, "%s: not found\n", *argv); 69520425Ssteve exitstatus = 127; 6961556Srgrimes flushout(&errout); 6971556Srgrimes return; 6981556Srgrimes } 6991556Srgrimes if (cmdentry.u.index != BLTINCMD) 7001556Srgrimes break; 7011556Srgrimes } 7021556Srgrimes } 7031556Srgrimes } 7041556Srgrimes 7051556Srgrimes /* Fork off a child process if necessary. */ 7061556Srgrimes if (cmd->ncmd.backgnd 70717987Speter || (cmdentry.cmdtype == CMDNORMAL && (flags & EV_EXIT) == 0) 70817987Speter || ((flags & EV_BACKCMD) != 0 7091556Srgrimes && (cmdentry.cmdtype != CMDBUILTIN 7101556Srgrimes || cmdentry.u.index == DOTCMD 71117987Speter || cmdentry.u.index == EVALCMD))) { 7121556Srgrimes jp = makejob(cmd, 1); 7131556Srgrimes mode = cmd->ncmd.backgnd; 7141556Srgrimes if (flags & EV_BACKCMD) { 7151556Srgrimes mode = FORK_NOJOB; 7161556Srgrimes if (pipe(pip) < 0) 7171556Srgrimes error("Pipe call failed"); 7181556Srgrimes } 7191556Srgrimes if (forkshell(jp, cmd, mode) != 0) 7201556Srgrimes goto parent; /* at end of routine */ 7211556Srgrimes if (flags & EV_BACKCMD) { 7221556Srgrimes FORCEINTON; 7231556Srgrimes close(pip[0]); 7241556Srgrimes if (pip[1] != 1) { 7251556Srgrimes close(1); 7261556Srgrimes copyfd(pip[1], 1); 7271556Srgrimes close(pip[1]); 7281556Srgrimes } 7291556Srgrimes } 7301556Srgrimes flags |= EV_EXIT; 7311556Srgrimes } 7321556Srgrimes 7331556Srgrimes /* This is the child process if a fork occurred. */ 7341556Srgrimes /* Execute the command. */ 7351556Srgrimes if (cmdentry.cmdtype == CMDFUNCTION) { 73620425Ssteve#ifdef DEBUG 7371556Srgrimes trputs("Shell function: "); trargs(argv); 73820425Ssteve#endif 7391556Srgrimes redirect(cmd->ncmd.redirect, REDIR_PUSH); 7401556Srgrimes saveparam = shellparam; 7411556Srgrimes shellparam.malloc = 0; 74220425Ssteve shellparam.reset = 1; 7431556Srgrimes shellparam.nparam = argc - 1; 7441556Srgrimes shellparam.p = argv + 1; 7451556Srgrimes shellparam.optnext = NULL; 7461556Srgrimes INTOFF; 7471556Srgrimes savelocalvars = localvars; 7481556Srgrimes localvars = NULL; 7491556Srgrimes INTON; 7501556Srgrimes if (setjmp(jmploc.loc)) { 7511556Srgrimes if (exception == EXSHELLPROC) 7521556Srgrimes freeparam((struct shparam *)&saveparam); 7531556Srgrimes else { 7541556Srgrimes freeparam(&shellparam); 7551556Srgrimes shellparam = saveparam; 7561556Srgrimes } 7571556Srgrimes poplocalvars(); 7581556Srgrimes localvars = savelocalvars; 7591556Srgrimes handler = savehandler; 7601556Srgrimes longjmp(handler->loc, 1); 7611556Srgrimes } 7621556Srgrimes savehandler = handler; 7631556Srgrimes handler = &jmploc; 7641556Srgrimes for (sp = varlist.list ; sp ; sp = sp->next) 7651556Srgrimes mklocal(sp->text); 7661556Srgrimes funcnest++; 7671556Srgrimes evaltree(cmdentry.u.func, 0); 7681556Srgrimes funcnest--; 7691556Srgrimes INTOFF; 7701556Srgrimes poplocalvars(); 7711556Srgrimes localvars = savelocalvars; 7721556Srgrimes freeparam(&shellparam); 7731556Srgrimes shellparam = saveparam; 7741556Srgrimes handler = savehandler; 7751556Srgrimes popredir(); 7761556Srgrimes INTON; 7771556Srgrimes if (evalskip == SKIPFUNC) { 7781556Srgrimes evalskip = 0; 7791556Srgrimes skipcount = 0; 7801556Srgrimes } 7811556Srgrimes if (flags & EV_EXIT) 7821556Srgrimes exitshell(exitstatus); 7831556Srgrimes } else if (cmdentry.cmdtype == CMDBUILTIN) { 78420425Ssteve#ifdef DEBUG 7851556Srgrimes trputs("builtin command: "); trargs(argv); 78620425Ssteve#endif 7871556Srgrimes mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; 7881556Srgrimes if (flags == EV_BACKCMD) { 7891556Srgrimes memout.nleft = 0; 7901556Srgrimes memout.nextc = memout.buf; 7911556Srgrimes memout.bufsize = 64; 7921556Srgrimes mode |= REDIR_BACKQ; 7931556Srgrimes } 7941556Srgrimes redirect(cmd->ncmd.redirect, mode); 7951556Srgrimes savecmdname = commandname; 7961556Srgrimes cmdenviron = varlist.list; 7971556Srgrimes e = -1; 7981556Srgrimes if (setjmp(jmploc.loc)) { 7991556Srgrimes e = exception; 8001556Srgrimes exitstatus = (e == EXINT)? SIGINT+128 : 2; 8011556Srgrimes goto cmddone; 8021556Srgrimes } 8031556Srgrimes savehandler = handler; 8041556Srgrimes handler = &jmploc; 8051556Srgrimes commandname = argv[0]; 8061556Srgrimes argptr = argv + 1; 8071556Srgrimes optptr = NULL; /* initialize nextopt */ 8081556Srgrimes exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); 8091556Srgrimes flushall(); 8101556Srgrimescmddone: 8111556Srgrimes out1 = &output; 8121556Srgrimes out2 = &errout; 8131556Srgrimes freestdout(); 8141556Srgrimes if (e != EXSHELLPROC) { 8151556Srgrimes commandname = savecmdname; 8161556Srgrimes if (flags & EV_EXIT) { 8171556Srgrimes exitshell(exitstatus); 8181556Srgrimes } 8191556Srgrimes } 8201556Srgrimes handler = savehandler; 8211556Srgrimes if (e != -1) { 82220425Ssteve if ((e != EXERROR && e != EXEXEC) 82320425Ssteve || cmdentry.u.index == BLTINCMD 82420425Ssteve || cmdentry.u.index == DOTCMD 82520425Ssteve || cmdentry.u.index == EVALCMD 82617987Speter#ifndef NO_HISTORY 82720425Ssteve || cmdentry.u.index == HISTCMD 82817987Speter#endif 82920425Ssteve || cmdentry.u.index == EXECCMD) 8301556Srgrimes exraise(e); 8311556Srgrimes FORCEINTON; 8321556Srgrimes } 8331556Srgrimes if (cmdentry.u.index != EXECCMD) 8341556Srgrimes popredir(); 8351556Srgrimes if (flags == EV_BACKCMD) { 8361556Srgrimes backcmd->buf = memout.buf; 8371556Srgrimes backcmd->nleft = memout.nextc - memout.buf; 8381556Srgrimes memout.buf = NULL; 8391556Srgrimes } 8401556Srgrimes } else { 84120425Ssteve#ifdef DEBUG 8421556Srgrimes trputs("normal command: "); trargs(argv); 84320425Ssteve#endif 8441556Srgrimes clearredir(); 8451556Srgrimes redirect(cmd->ncmd.redirect, 0); 8461556Srgrimes for (sp = varlist.list ; sp ; sp = sp->next) 8471556Srgrimes setvareq(sp->text, VEXPORT|VSTACK); 8481556Srgrimes envp = environment(); 84917987Speter shellexec(argv, envp, pathval(), cmdentry.u.index); 8501556Srgrimes /*NOTREACHED*/ 8511556Srgrimes } 8521556Srgrimes goto out; 8531556Srgrimes 8541556Srgrimesparent: /* parent process gets here (if we forked) */ 8551556Srgrimes if (mode == 0) { /* argument to fork */ 8561556Srgrimes INTOFF; 85719683Speter exitstatus = waitforjob(jp); 8581556Srgrimes INTON; 8591556Srgrimes } else if (mode == 2) { 8601556Srgrimes backcmd->fd = pip[0]; 8611556Srgrimes close(pip[1]); 8621556Srgrimes backcmd->jp = jp; 8631556Srgrimes } 8641556Srgrimes 8651556Srgrimesout: 8661556Srgrimes if (lastarg) 8671556Srgrimes setvar("_", lastarg, 0); 8681556Srgrimes popstackmark(&smark); 8691556Srgrimes} 8701556Srgrimes 8711556Srgrimes 8721556Srgrimes 8731556Srgrimes/* 8741556Srgrimes * Search for a command. This is called before we fork so that the 8751556Srgrimes * location of the command will be available in the parent as well as 8761556Srgrimes * the child. The check for "goodname" is an overly conservative 8771556Srgrimes * check that the name will not be subject to expansion. 8781556Srgrimes */ 8791556Srgrimes 8801556SrgrimesSTATIC void 8811556Srgrimesprehash(n) 8821556Srgrimes union node *n; 88317987Speter{ 8841556Srgrimes struct cmdentry entry; 8851556Srgrimes 88617987Speter if (n->type == NCMD && n->ncmd.args) 88717987Speter if (goodname(n->ncmd.args->narg.text)) 88817987Speter find_command(n->ncmd.args->narg.text, &entry, 0, 88917987Speter pathval()); 8901556Srgrimes} 8911556Srgrimes 8921556Srgrimes 8931556Srgrimes 8941556Srgrimes/* 8951556Srgrimes * Builtin commands. Builtin commands whose functions are closely 8961556Srgrimes * tied to evaluation are implemented here. 8971556Srgrimes */ 8981556Srgrimes 8991556Srgrimes/* 9001556Srgrimes * No command given, or a bltin command with no arguments. Set the 9011556Srgrimes * specified variables. 9021556Srgrimes */ 9031556Srgrimes 90417987Speterint 90517987Speterbltincmd(argc, argv) 90617987Speter int argc; 90720425Ssteve char **argv; 90817987Speter{ 9091556Srgrimes listsetvar(cmdenviron); 91020425Ssteve /* 91117987Speter * Preserve exitstatus of a previous possible redirection 91220425Ssteve * as POSIX mandates 91317987Speter */ 9141556Srgrimes return exitstatus; 9151556Srgrimes} 9161556Srgrimes 9171556Srgrimes 9181556Srgrimes/* 9191556Srgrimes * Handle break and continue commands. Break, continue, and return are 9201556Srgrimes * all handled by setting the evalskip flag. The evaluation routines 9211556Srgrimes * above all check this flag, and if it is set they start skipping 9221556Srgrimes * commands rather than executing them. The variable skipcount is 9231556Srgrimes * the number of loops to break/continue, or the number of function 9241556Srgrimes * levels to return. (The latter is always 1.) It should probably 9251556Srgrimes * be an error to break out of more loops than exist, but it isn't 9261556Srgrimes * in the standard shell so we don't make it one here. 9271556Srgrimes */ 9281556Srgrimes 92917987Speterint 93017987Speterbreakcmd(argc, argv) 93117987Speter int argc; 93220425Ssteve char **argv; 93317987Speter{ 93420425Ssteve int n = argc > 1 ? number(argv[1]) : 1; 9351556Srgrimes 9361556Srgrimes if (n > loopnest) 9371556Srgrimes n = loopnest; 9381556Srgrimes if (n > 0) { 9391556Srgrimes evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 9401556Srgrimes skipcount = n; 9411556Srgrimes } 9421556Srgrimes return 0; 9431556Srgrimes} 9441556Srgrimes 9451556Srgrimes 9461556Srgrimes/* 9471556Srgrimes * The return command. 9481556Srgrimes */ 9491556Srgrimes 95017987Speterint 95120425Sstevereturncmd(argc, argv) 95217987Speter int argc; 95320425Ssteve char **argv; 95417987Speter{ 95520425Ssteve int ret = argc > 1 ? number(argv[1]) : oexitstatus; 9561556Srgrimes 9571556Srgrimes if (funcnest) { 9581556Srgrimes evalskip = SKIPFUNC; 9591556Srgrimes skipcount = 1; 96020425Ssteve } else { 96120425Ssteve /* skip the rest of the file */ 96220425Ssteve evalskip = SKIPFILE; 96320425Ssteve skipcount = 1; 9641556Srgrimes } 9651556Srgrimes return ret; 9661556Srgrimes} 9671556Srgrimes 9681556Srgrimes 96917987Speterint 97020425Sstevefalsecmd(argc, argv) 97117987Speter int argc; 97220425Ssteve char **argv; 97317987Speter{ 97417987Speter return 1; 97517987Speter} 97617987Speter 97717987Speter 97817987Speterint 97920425Sstevetruecmd(argc, argv) 98017987Speter int argc; 98120425Ssteve char **argv; 98217987Speter{ 9831556Srgrimes return 0; 9841556Srgrimes} 9851556Srgrimes 9861556Srgrimes 98717987Speterint 98820425Ssteveexeccmd(argc, argv) 98917987Speter int argc; 99020425Ssteve char **argv; 99117987Speter{ 9921556Srgrimes if (argc > 1) { 99317987Speter struct strlist *sp; 99417987Speter 9951556Srgrimes iflag = 0; /* exit on error */ 9961556Srgrimes mflag = 0; 9971556Srgrimes optschanged(); 99817987Speter for (sp = cmdenviron; sp ; sp = sp->next) 99917987Speter setvareq(sp->text, VEXPORT|VSTACK); 10001556Srgrimes shellexec(argv + 1, environment(), pathval(), 0); 10011556Srgrimes 10021556Srgrimes } 10031556Srgrimes return 0; 10041556Srgrimes} 1005