parser.c revision 100483
1232633Smp/*- 259243Sobrien * Copyright (c) 1991, 1993 359243Sobrien * The Regents of the University of California. All rights reserved. 459243Sobrien * 559243Sobrien * This code is derived from software contributed to Berkeley by 659243Sobrien * Kenneth Almquist. 759243Sobrien * 859243Sobrien * Redistribution and use in source and binary forms, with or without 959243Sobrien * modification, are permitted provided that the following conditions 1059243Sobrien * are met: 1159243Sobrien * 1. Redistributions of source code must retain the above copyright 1259243Sobrien * notice, this list of conditions and the following disclaimer. 1359243Sobrien * 2. Redistributions in binary form must reproduce the above copyright 1459243Sobrien * notice, this list of conditions and the following disclaimer in the 1559243Sobrien * documentation and/or other materials provided with the distribution. 1659243Sobrien * 3. All advertising materials mentioning features or use of this software 17100616Smp * must display the following acknowledgement: 1859243Sobrien * This product includes software developed by the University of 1959243Sobrien * California, Berkeley and its contributors. 2059243Sobrien * 4. Neither the name of the University nor the names of its contributors 2159243Sobrien * may be used to endorse or promote products derived from this software 2259243Sobrien * without specific prior written permission. 2359243Sobrien * 2459243Sobrien * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2559243Sobrien * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2659243Sobrien * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2759243Sobrien * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2859243Sobrien * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2959243Sobrien * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 3059243Sobrien * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 3159243Sobrien * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 3259243Sobrien * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3359243Sobrien * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3459243Sobrien * SUCH DAMAGE. 35232633Smp */ 3659243Sobrien 3759243Sobrien#ifndef lint 3859243Sobrien#if 0 3959243Sobrienstatic char sccsid[] = "@(#)parser.c 8.7 (Berkeley) 5/16/95"; 40167465Smp#endif 41167465Smp#endif /* not lint */ 42167465Smp#include <sys/cdefs.h> 43167465Smp__FBSDID("$FreeBSD: head/bin/sh/parser.c 100483 2002-07-22 05:50:12Z tjr $"); 44167465Smp 45167465Smp#include <stdlib.h> 46167465Smp 47167465Smp#include "shell.h" 48167465Smp#include "parser.h" 49167465Smp#include "nodes.h" 5059243Sobrien#include "expand.h" /* defines rmescapes() */ 5159243Sobrien#include "redir.h" /* defines copyfd() */ 5259243Sobrien#include "syntax.h" 5359243Sobrien#include "options.h" 5459243Sobrien#include "input.h" 5559243Sobrien#include "output.h" 5659243Sobrien#include "var.h" 5759243Sobrien#include "error.h" 5859243Sobrien#include "memalloc.h" 5959243Sobrien#include "mystring.h" 6059243Sobrien#include "alias.h" 61167465Smp#include "show.h" 6259243Sobrien#include "eval.h" 63167465Smp#ifndef NO_HISTORY 6459243Sobrien#include "myhistedit.h" 6559243Sobrien#endif 6659243Sobrien 67167465Smp/* 68167465Smp * Shell command parser. 69167465Smp */ 70167465Smp 7159243Sobrien#define EOFMARKLEN 79 7259243Sobrien 73167465Smp/* values returned by readtoken */ 74167465Smp#include "token.h" 7559243Sobrien 76167465Smp 77167465Smp 78167465Smpstruct heredoc { 79167465Smp struct heredoc *next; /* next here document in list */ 80167465Smp union node *here; /* redirection node */ 81167465Smp char *eofmark; /* string indicating end of input */ 8259243Sobrien int striptabs; /* if set, strip leading tabs */ 8359243Sobrien}; 84167465Smp 85167465Smp 8659243Sobrien 87145479Smpstruct heredoc *heredoclist; /* list of here documents to read */ 88145479Smpint parsebackquote; /* nonzero if we are inside backquotes */ 8959243Sobrienint doprompt; /* if set, prompt the user */ 9059243Sobrienint needprompt; /* true if interactive and at start of line */ 9159243Sobrienint lasttoken; /* last token read */ 9259243SobrienMKINIT int tokpushback; /* last token pushed back */ 9359243Sobrienchar *wordtext; /* text of last word returned by readtoken */ 9459243SobrienMKINIT int checkkwd; /* 1 == check for kwds, 2 == also eat newlines */ 9559243Sobrienstruct nodelist *backquotelist; 9659243Sobrienunion node *redirnode; 9759243Sobrienstruct heredoc *heredoc; 9859243Sobrienint quoteflag; /* set if (part of) last token was quoted */ 9959243Sobrienint startlinno; /* line # where last token started */ 10059243Sobrien 10159243Sobrien/* XXX When 'noaliases' is set to one, no alias expansion takes place. */ 10259243Sobrienstatic int noaliases = 0; 10359243Sobrien 10459243Sobrien#define GDB_HACK 1 /* avoid local declarations which gdb can't handle */ 10559243Sobrien#ifdef GDB_HACK 10659243Sobrienstatic const char argvars[5] = {CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0'}; 10759243Sobrienstatic const char types[] = "}-+?="; 10859243Sobrien#endif 10959243Sobrien 11059243Sobrien 11159243SobrienSTATIC union node *list(int); 11259243SobrienSTATIC union node *andor(void); 11359243SobrienSTATIC union node *pipeline(void); 114167465SmpSTATIC union node *command(void); 115167465SmpSTATIC union node *simplecmd(union node **, union node *); 116167465SmpSTATIC union node *makename(void); 11759243SobrienSTATIC void parsefname(void); 11859243SobrienSTATIC void parseheredoc(void); 11959243SobrienSTATIC int peektoken(void); 12059243SobrienSTATIC int readtoken(void); 12159243SobrienSTATIC int xxreadtoken(void); 122167465SmpSTATIC int readtoken1(int, char const *, char *, int); 123167465SmpSTATIC int noexpand(char *); 12459243SobrienSTATIC void synexpect(int); 12559243SobrienSTATIC void synerror(char *); 12659243SobrienSTATIC void setprompt(int); 127167465Smp 12859243Sobrien 129167465Smp/* 130167465Smp * Read and parse a command. Returns NEOF on end of file. (NULL is a 131167465Smp * valid parse tree indicating a blank line.) 132167465Smp */ 133167465Smp 134167465Smpunion node * 135167465Smpparsecmd(int interact) 136167465Smp{ 137167465Smp int t; 138145479Smp 13959243Sobrien tokpushback = 0; 140145479Smp doprompt = interact; 14159243Sobrien if (doprompt) 14259243Sobrien setprompt(1); 143167465Smp else 14459243Sobrien setprompt(0); 14559243Sobrien needprompt = 0; 14659243Sobrien t = readtoken(); 147167465Smp if (t == TEOF) 14859243Sobrien return NEOF; 149167465Smp if (t == TNL) 150167465Smp return NULL; 15159243Sobrien tokpushback++; 15259243Sobrien return list(1); 15359243Sobrien} 154167465Smp 15559243Sobrien 15659243SobrienSTATIC union node * 15759243Sobrienlist(int nlflag) 158167465Smp{ 15959243Sobrien union node *n1, *n2, *n3; 160167465Smp int tok; 16159243Sobrien 16259243Sobrien checkkwd = 2; 16359243Sobrien if (nlflag == 0 && tokendlist[peektoken()]) 16459243Sobrien return NULL; 16559243Sobrien n1 = NULL; 16659243Sobrien for (;;) { 16759243Sobrien n2 = andor(); 16859243Sobrien tok = readtoken(); 169167465Smp if (tok == TBACKGND) { 17059243Sobrien if (n2->type == NCMD || n2->type == NPIPE) { 17159243Sobrien n2->ncmd.backgnd = 1; 17259243Sobrien } else if (n2->type == NREDIR) { 17359243Sobrien n2->type = NBACKGND; 17459243Sobrien } else { 17559243Sobrien n3 = (union node *)stalloc(sizeof (struct nredir)); 17659243Sobrien n3->type = NBACKGND; 177167465Smp n3->nredir.n = n2; 178167465Smp n3->nredir.redirect = NULL; 17959243Sobrien n2 = n3; 180167465Smp } 18159243Sobrien } 18259243Sobrien if (n1 == NULL) { 18359243Sobrien n1 = n2; 184167465Smp } 18559243Sobrien else { 186145479Smp n3 = (union node *)stalloc(sizeof (struct nbinary)); 18759243Sobrien n3->type = NSEMI; 18859243Sobrien n3->nbinary.ch1 = n1; 189167465Smp n3->nbinary.ch2 = n2; 19059243Sobrien n1 = n3; 191167465Smp } 19259243Sobrien switch (tok) { 19359243Sobrien case TBACKGND: 19459243Sobrien case TSEMI: 19559243Sobrien tok = readtoken(); 19659243Sobrien /* fall through */ 19759243Sobrien case TNL: 19859243Sobrien if (tok == TNL) { 19959243Sobrien parseheredoc(); 20059243Sobrien if (nlflag) 20159243Sobrien return n1; 20259243Sobrien } else { 20359243Sobrien tokpushback++; 20459243Sobrien } 20559243Sobrien checkkwd = 2; 20659243Sobrien if (tokendlist[peektoken()]) 20759243Sobrien return n1; 20859243Sobrien break; 209167465Smp case TEOF: 21059243Sobrien if (heredoclist) 21159243Sobrien parseheredoc(); 21259243Sobrien else 21359243Sobrien pungetc(); /* push back EOF on input */ 21459243Sobrien return n1; 21559243Sobrien default: 21659243Sobrien if (nlflag) 21759243Sobrien synexpect(-1); 21859243Sobrien tokpushback++; 21959243Sobrien return n1; 22059243Sobrien } 22159243Sobrien } 22259243Sobrien} 22359243Sobrien 22459243Sobrien 22559243Sobrien 226167465SmpSTATIC union node * 22759243Sobrienandor(void) 228167465Smp{ 229145479Smp union node *n1, *n2, *n3; 23059243Sobrien int t; 23159243Sobrien 23259243Sobrien n1 = pipeline(); 23359243Sobrien for (;;) { 23459243Sobrien if ((t = readtoken()) == TAND) { 23559243Sobrien t = NAND; 23659243Sobrien } else if (t == TOR) { 23759243Sobrien t = NOR; 23859243Sobrien } else { 23959243Sobrien tokpushback++; 24059243Sobrien return n1; 24159243Sobrien } 24259243Sobrien n2 = pipeline(); 24359243Sobrien n3 = (union node *)stalloc(sizeof (struct nbinary)); 24459243Sobrien n3->type = t; 24559243Sobrien n3->nbinary.ch1 = n1; 24659243Sobrien n3->nbinary.ch2 = n2; 24759243Sobrien n1 = n3; 24859243Sobrien } 24959243Sobrien} 25059243Sobrien 25159243Sobrien 25259243Sobrien 25359243SobrienSTATIC union node * 25459243Sobrienpipeline(void) 25559243Sobrien{ 25659243Sobrien union node *n1, *n2, *pipenode; 25759243Sobrien struct nodelist *lp, *prev; 25859243Sobrien int negate; 25959243Sobrien 26059243Sobrien negate = 0; 26159243Sobrien TRACE(("pipeline: entered\n")); 26259243Sobrien while (readtoken() == TNOT) 26359243Sobrien negate = !negate; 26459243Sobrien tokpushback++; 265167465Smp n1 = command(); 26659243Sobrien if (readtoken() == TPIPE) { 26759243Sobrien pipenode = (union node *)stalloc(sizeof (struct npipe)); 26859243Sobrien pipenode->type = NPIPE; 26959243Sobrien pipenode->npipe.backgnd = 0; 27059243Sobrien lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 27159243Sobrien pipenode->npipe.cmdlist = lp; 27259243Sobrien lp->n = n1; 273167465Smp do { 27459243Sobrien prev = lp; 27559243Sobrien lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 27659243Sobrien lp->n = command(); 27759243Sobrien prev->next = lp; 27859243Sobrien } while (readtoken() == TPIPE); 27959243Sobrien lp->next = NULL; 28059243Sobrien n1 = pipenode; 28159243Sobrien } 28259243Sobrien tokpushback++; 28359243Sobrien if (negate) { 28459243Sobrien n2 = (union node *)stalloc(sizeof (struct nnot)); 28559243Sobrien n2->type = NNOT; 28659243Sobrien n2->nnot.com = n1; 28759243Sobrien return n2; 28859243Sobrien } else 28959243Sobrien return n1; 29059243Sobrien} 29159243Sobrien 29259243Sobrien 29359243Sobrien 294167465SmpSTATIC union node * 29559243Sobriencommand(void) 296167465Smp{ 297145479Smp union node *n1, *n2; 29859243Sobrien union node *ap, **app; 29959243Sobrien union node *cp, **cpp; 30059243Sobrien union node *redir, **rpp; 30159243Sobrien int t, negate = 0; 30259243Sobrien 30359243Sobrien checkkwd = 2; 30459243Sobrien redir = NULL; 30559243Sobrien n1 = NULL; 30659243Sobrien rpp = &redir; 30759243Sobrien 30859243Sobrien /* Check for redirection which may precede command */ 30959243Sobrien while (readtoken() == TREDIR) { 31059243Sobrien *rpp = n2 = redirnode; 31159243Sobrien rpp = &n2->nfile.next; 31259243Sobrien parsefname(); 31359243Sobrien } 31459243Sobrien tokpushback++; 31559243Sobrien 316167465Smp while (readtoken() == TNOT) { 31759243Sobrien TRACE(("command: TNOT recognized\n")); 31859243Sobrien negate = !negate; 31959243Sobrien } 32059243Sobrien tokpushback++; 32159243Sobrien 32259243Sobrien switch (readtoken()) { 32359243Sobrien case TIF: 32459243Sobrien n1 = (union node *)stalloc(sizeof (struct nif)); 32559243Sobrien n1->type = NIF; 32659243Sobrien n1->nif.test = list(0); 32759243Sobrien if (readtoken() != TTHEN) 32859243Sobrien synexpect(TTHEN); 32959243Sobrien n1->nif.ifpart = list(0); 33059243Sobrien n2 = n1; 33159243Sobrien while (readtoken() == TELIF) { 33259243Sobrien n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); 33359243Sobrien n2 = n2->nif.elsepart; 33459243Sobrien n2->type = NIF; 33559243Sobrien n2->nif.test = list(0); 336167465Smp if (readtoken() != TTHEN) 33759243Sobrien synexpect(TTHEN); 338167465Smp n2->nif.ifpart = list(0); 339145479Smp } 340145479Smp if (lasttoken == TELSE) 34159243Sobrien n2->nif.elsepart = list(0); 34259243Sobrien else { 34359243Sobrien n2->nif.elsepart = NULL; 34459243Sobrien tokpushback++; 34559243Sobrien } 34659243Sobrien if (readtoken() != TFI) 34759243Sobrien synexpect(TFI); 34859243Sobrien checkkwd = 1; 34959243Sobrien break; 35059243Sobrien case TWHILE: 35159243Sobrien case TUNTIL: { 35259243Sobrien int got; 35359243Sobrien n1 = (union node *)stalloc(sizeof (struct nbinary)); 35459243Sobrien n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL; 35559243Sobrien n1->nbinary.ch1 = list(0); 35659243Sobrien if ((got=readtoken()) != TDO) { 357167465SmpTRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : "")); 35859243Sobrien synexpect(TDO); 35959243Sobrien } 36059243Sobrien n1->nbinary.ch2 = list(0); 36159243Sobrien if (readtoken() != TDONE) 36259243Sobrien synexpect(TDONE); 36359243Sobrien checkkwd = 1; 36459243Sobrien break; 36559243Sobrien } 36659243Sobrien case TFOR: 36759243Sobrien if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) 36859243Sobrien synerror("Bad for loop variable"); 36959243Sobrien n1 = (union node *)stalloc(sizeof (struct nfor)); 37059243Sobrien n1->type = NFOR; 37159243Sobrien n1->nfor.var = wordtext; 37259243Sobrien if (readtoken() == TWORD && ! quoteflag && equal(wordtext, "in")) { 37359243Sobrien app = ≈ 37459243Sobrien while (readtoken() == TWORD) { 37559243Sobrien n2 = (union node *)stalloc(sizeof (struct narg)); 37659243Sobrien n2->type = NARG; 37759243Sobrien n2->narg.text = wordtext; 378167465Smp n2->narg.backquote = backquotelist; 37959243Sobrien *app = n2; 380167465Smp app = &n2->narg.next; 381145479Smp } 382145479Smp *app = NULL; 38359243Sobrien n1->nfor.args = ap; 38459243Sobrien if (lasttoken != TNL && lasttoken != TSEMI) 38559243Sobrien synexpect(-1); 38659243Sobrien } else { 38759243Sobrien#ifndef GDB_HACK 38859243Sobrien static const char argvars[5] = {CTLVAR, VSNORMAL|VSQUOTE, 38959243Sobrien '@', '=', '\0'}; 39059243Sobrien#endif 39159243Sobrien n2 = (union node *)stalloc(sizeof (struct narg)); 39259243Sobrien n2->type = NARG; 39359243Sobrien n2->narg.text = (char *)argvars; 39459243Sobrien n2->narg.backquote = NULL; 39559243Sobrien n2->narg.next = NULL; 39659243Sobrien n1->nfor.args = n2; 397167465Smp /* 39859243Sobrien * Newline or semicolon here is optional (but note 39959243Sobrien * that the original Bourne shell only allowed NL). 40059243Sobrien */ 40159243Sobrien if (lasttoken != TNL && lasttoken != TSEMI) 40259243Sobrien tokpushback++; 40359243Sobrien } 40459243Sobrien checkkwd = 2; 40559243Sobrien if ((t = readtoken()) == TDO) 40659243Sobrien t = TDONE; 40759243Sobrien else if (t == TBEGIN) 40859243Sobrien t = TEND; 40959243Sobrien else 41059243Sobrien synexpect(-1); 41159243Sobrien n1->nfor.body = list(0); 41259243Sobrien if (readtoken() != t) 41359243Sobrien synexpect(t); 41459243Sobrien checkkwd = 1; 41559243Sobrien break; 41659243Sobrien case TCASE: 41759243Sobrien n1 = (union node *)stalloc(sizeof (struct ncase)); 41859243Sobrien n1->type = NCASE; 419167465Smp if (readtoken() != TWORD) 42059243Sobrien synexpect(TWORD); 421167465Smp n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg)); 422145479Smp n2->type = NARG; 423145479Smp n2->narg.text = wordtext; 42459243Sobrien n2->narg.backquote = backquotelist; 42559243Sobrien n2->narg.next = NULL; 42659243Sobrien while (readtoken() == TNL); 42759243Sobrien if (lasttoken != TWORD || ! equal(wordtext, "in")) 42859243Sobrien synerror("expecting \"in\""); 42959243Sobrien cpp = &n1->ncase.cases; 43059243Sobrien noaliases = 1; /* turn off alias expansion */ 43159243Sobrien checkkwd = 2, readtoken(); 43259243Sobrien do { 43359243Sobrien *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); 43459243Sobrien cp->type = NCLIST; 43559243Sobrien app = &cp->nclist.pattern; 43659243Sobrien for (;;) { 43759243Sobrien *app = ap = (union node *)stalloc(sizeof (struct narg)); 43859243Sobrien ap->type = NARG; 43959243Sobrien ap->narg.text = wordtext; 440167465Smp ap->narg.backquote = backquotelist; 44159243Sobrien if (checkkwd = 2, readtoken() != TPIPE) 44259243Sobrien break; 44359243Sobrien app = &ap->narg.next; 44459243Sobrien readtoken(); 44559243Sobrien } 44659243Sobrien ap->narg.next = NULL; 44759243Sobrien if (lasttoken != TRP) 44859243Sobrien noaliases = 0, synexpect(TRP); 44959243Sobrien cp->nclist.body = list(0); 45059243Sobrien 45159243Sobrien checkkwd = 2; 45259243Sobrien if ((t = readtoken()) != TESAC) { 45359243Sobrien if (t != TENDCASE) 45459243Sobrien noaliases = 0, synexpect(TENDCASE); 45559243Sobrien else 45659243Sobrien checkkwd = 2, readtoken(); 45759243Sobrien } 45859243Sobrien cpp = &cp->nclist.next; 45959243Sobrien } while(lasttoken != TESAC); 460167465Smp noaliases = 0; /* reset alias expansion */ 46159243Sobrien *cpp = NULL; 46259243Sobrien checkkwd = 1; 46359243Sobrien break; 46459243Sobrien case TLP: 46559243Sobrien n1 = (union node *)stalloc(sizeof (struct nredir)); 46659243Sobrien n1->type = NSUBSHELL; 46759243Sobrien n1->nredir.n = list(0); 46859243Sobrien n1->nredir.redirect = NULL; 46959243Sobrien if (readtoken() != TRP) 47059243Sobrien synexpect(TRP); 471167465Smp checkkwd = 1; 47259243Sobrien break; 473167465Smp case TBEGIN: 474167465Smp n1 = list(0); 475145479Smp if (readtoken() != TEND) 476145479Smp synexpect(TEND); 47759243Sobrien checkkwd = 1; 47859243Sobrien break; 479145479Smp /* Handle an empty command like other simple commands. */ 48059243Sobrien case TSEMI: 48159243Sobrien /* 48259243Sobrien * An empty command before a ; doesn't make much sense, and 48359243Sobrien * should certainly be disallowed in the case of `if ;'. 48459243Sobrien */ 48559243Sobrien if (!redir) 48659243Sobrien synexpect(-1); 48759243Sobrien case TAND: 48859243Sobrien case TOR: 48959243Sobrien synexpect(-1); 49059243Sobrien case TNL: 49159243Sobrien case TEOF: 49259243Sobrien case TWORD: 49359243Sobrien case TRP: 49459243Sobrien tokpushback++; 49559243Sobrien n1 = simplecmd(rpp, redir); 49659243Sobrien goto checkneg; 49759243Sobrien default: 49859243Sobrien synexpect(-1); 49959243Sobrien } 50059243Sobrien 50159243Sobrien /* Now check for redirection which may follow command */ 50259243Sobrien while (readtoken() == TREDIR) { 50359243Sobrien *rpp = n2 = redirnode; 50459243Sobrien rpp = &n2->nfile.next; 50559243Sobrien parsefname(); 50659243Sobrien } 50759243Sobrien tokpushback++; 50859243Sobrien *rpp = NULL; 50959243Sobrien if (redir) { 51059243Sobrien if (n1->type != NSUBSHELL) { 51159243Sobrien n2 = (union node *)stalloc(sizeof (struct nredir)); 51259243Sobrien n2->type = NREDIR; 51359243Sobrien n2->nredir.n = n1; 51459243Sobrien n1 = n2; 51559243Sobrien } 51659243Sobrien n1->nredir.redirect = redir; 51759243Sobrien } 51859243Sobrien 51959243Sobriencheckneg: 52059243Sobrien if (negate) { 52159243Sobrien n2 = (union node *)stalloc(sizeof (struct nnot)); 52259243Sobrien n2->type = NNOT; 52359243Sobrien n2->nnot.com = n1; 52459243Sobrien return n2; 52559243Sobrien } 52659243Sobrien else 52759243Sobrien return n1; 52859243Sobrien} 52959243Sobrien 53059243Sobrien 53159243SobrienSTATIC union node * 53259243Sobriensimplecmd(union node **rpp, union node *redir) 53359243Sobrien{ 53459243Sobrien union node *args, **app; 53559243Sobrien union node **orig_rpp = rpp; 53659243Sobrien union node *n = NULL, *n2; 53759243Sobrien int negate = 0; 53859243Sobrien 53959243Sobrien /* If we don't have any redirections already, then we must reset */ 54059243Sobrien /* rpp to be the address of the local redir variable. */ 54159243Sobrien if (redir == 0) 54259243Sobrien rpp = &redir; 54359243Sobrien 544167465Smp args = NULL; 545167465Smp app = &args; 54659243Sobrien /* 54759243Sobrien * We save the incoming value, because we need this for shell 54859243Sobrien * functions. There can not be a redirect or an argument between 54959243Sobrien * the function name and the open parenthesis. 55059243Sobrien */ 55159243Sobrien orig_rpp = rpp; 55259243Sobrien 55359243Sobrien while (readtoken() == TNOT) { 55459243Sobrien TRACE(("command: TNOT recognized\n")); 55559243Sobrien negate = !negate; 55659243Sobrien } 55759243Sobrien tokpushback++; 55859243Sobrien 55959243Sobrien for (;;) { 56059243Sobrien if (readtoken() == TWORD) { 56159243Sobrien n = (union node *)stalloc(sizeof (struct narg)); 56259243Sobrien n->type = NARG; 56359243Sobrien n->narg.text = wordtext; 56459243Sobrien n->narg.backquote = backquotelist; 56559243Sobrien *app = n; 56659243Sobrien app = &n->narg.next; 56759243Sobrien } else if (lasttoken == TREDIR) { 56859243Sobrien *rpp = n = redirnode; 56959243Sobrien rpp = &n->nfile.next; 57059243Sobrien parsefname(); /* read name of redirection file */ 57159243Sobrien } else if (lasttoken == TLP && app == &args->narg.next 57259243Sobrien && rpp == orig_rpp) { 57359243Sobrien /* We have a function */ 57459243Sobrien if (readtoken() != TRP) 57559243Sobrien synexpect(TRP); 57659243Sobrien#ifdef notdef 57759243Sobrien if (! goodname(n->narg.text)) 57859243Sobrien synerror("Bad function name"); 57959243Sobrien#endif 58059243Sobrien n->type = NDEFUN; 58159243Sobrien n->narg.next = command(); 58259243Sobrien goto checkneg; 58359243Sobrien } else { 58459243Sobrien tokpushback++; 58559243Sobrien break; 58659243Sobrien } 58759243Sobrien } 58859243Sobrien *app = NULL; 58959243Sobrien *rpp = NULL; 59059243Sobrien n = (union node *)stalloc(sizeof (struct ncmd)); 59159243Sobrien n->type = NCMD; 59259243Sobrien n->ncmd.backgnd = 0; 59359243Sobrien n->ncmd.args = args; 59459243Sobrien n->ncmd.redirect = redir; 59559243Sobrien 59659243Sobriencheckneg: 59759243Sobrien if (negate) { 59859243Sobrien n2 = (union node *)stalloc(sizeof (struct nnot)); 59959243Sobrien n2->type = NNOT; 60059243Sobrien n2->nnot.com = n; 60159243Sobrien return n2; 60259243Sobrien } 60359243Sobrien else 60459243Sobrien return n; 60559243Sobrien} 60659243Sobrien 60759243SobrienSTATIC union node * 60859243Sobrienmakename(void) 60959243Sobrien{ 61059243Sobrien union node *n; 61159243Sobrien 61259243Sobrien n = (union node *)stalloc(sizeof (struct narg)); 61359243Sobrien n->type = NARG; 61459243Sobrien n->narg.next = NULL; 61559243Sobrien n->narg.text = wordtext; 61659243Sobrien n->narg.backquote = backquotelist; 61759243Sobrien return n; 61859243Sobrien} 61959243Sobrien 62059243Sobrienvoid fixredir(union node *n, const char *text, int err) 62159243Sobrien{ 62259243Sobrien TRACE(("Fix redir %s %d\n", text, err)); 62359243Sobrien if (!err) 62459243Sobrien n->ndup.vname = NULL; 62559243Sobrien 62659243Sobrien if (is_digit(text[0]) && text[1] == '\0') 62759243Sobrien n->ndup.dupfd = digit_val(text[0]); 62859243Sobrien else if (text[0] == '-' && text[1] == '\0') 62959243Sobrien n->ndup.dupfd = -1; 63059243Sobrien else { 63159243Sobrien 63259243Sobrien if (err) 63359243Sobrien synerror("Bad fd number"); 63459243Sobrien else 63559243Sobrien n->ndup.vname = makename(); 63659243Sobrien } 63759243Sobrien} 63859243Sobrien 63959243Sobrien 64059243SobrienSTATIC void 64159243Sobrienparsefname(void) 64259243Sobrien{ 64359243Sobrien union node *n = redirnode; 64459243Sobrien 64559243Sobrien if (readtoken() != TWORD) 64659243Sobrien synexpect(-1); 64759243Sobrien if (n->type == NHERE) { 64859243Sobrien struct heredoc *here = heredoc; 64959243Sobrien struct heredoc *p; 650167465Smp int i; 65159243Sobrien 652145479Smp if (quoteflag == 0) 65359243Sobrien n->type = NXHERE; 65459243Sobrien TRACE(("Here document %d\n", n->type)); 65559243Sobrien if (here->striptabs) { 65659243Sobrien while (*wordtext == '\t') 65759243Sobrien wordtext++; 65859243Sobrien } 65959243Sobrien if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) 660167465Smp synerror("Illegal eof marker for << redirection"); 661167465Smp rmescapes(wordtext); 662167465Smp here->eofmark = wordtext; 663167465Smp here->next = NULL; 66459243Sobrien if (heredoclist == NULL) 66559243Sobrien heredoclist = here; 66659243Sobrien else { 667167465Smp for (p = heredoclist ; p->next ; p = p->next); 668167465Smp p->next = here; 66959243Sobrien } 67059243Sobrien } else if (n->type == NTOFD || n->type == NFROMFD) { 67159243Sobrien fixredir(n, wordtext, 0); 67259243Sobrien } else { 67359243Sobrien n->nfile.fname = makename(); 67459243Sobrien } 67559243Sobrien} 67659243Sobrien 67759243Sobrien 67859243Sobrien/* 67959243Sobrien * Input any here documents. 680232633Smp */ 681232633Smp 682232633SmpSTATIC void 683167465Smpparseheredoc(void) 68459243Sobrien{ 685167465Smp struct heredoc *here; 686167465Smp union node *n; 687167465Smp 688167465Smp while (heredoclist) { 689167465Smp here = heredoclist; 690167465Smp heredoclist = here->next; 691167465Smp if (needprompt) { 692167465Smp setprompt(2); 693167465Smp needprompt = 0; 694 } 695 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 696 here->eofmark, here->striptabs); 697 n = (union node *)stalloc(sizeof (struct narg)); 698 n->narg.type = NARG; 699 n->narg.next = NULL; 700 n->narg.text = wordtext; 701 n->narg.backquote = backquotelist; 702 here->here->nhere.doc = n; 703 } 704} 705 706STATIC int 707peektoken(void) 708{ 709 int t; 710 711 t = readtoken(); 712 tokpushback++; 713 return (t); 714} 715 716STATIC int 717readtoken(void) 718{ 719 int t; 720 int savecheckkwd = checkkwd; 721 struct alias *ap; 722#ifdef DEBUG 723 int alreadyseen = tokpushback; 724#endif 725 726 top: 727 t = xxreadtoken(); 728 729 if (checkkwd) { 730 /* 731 * eat newlines 732 */ 733 if (checkkwd == 2) { 734 checkkwd = 0; 735 while (t == TNL) { 736 parseheredoc(); 737 t = xxreadtoken(); 738 } 739 } else 740 checkkwd = 0; 741 /* 742 * check for keywords and aliases 743 */ 744 if (t == TWORD && !quoteflag) 745 { 746 const char * const *pp; 747 748 for (pp = parsekwd; *pp; pp++) { 749 if (**pp == *wordtext && equal(*pp, wordtext)) 750 { 751 lasttoken = t = pp - parsekwd + KWDOFFSET; 752 TRACE(("keyword %s recognized\n", tokname[t])); 753 goto out; 754 } 755 } 756 if (noaliases == 0 && 757 (ap = lookupalias(wordtext, 1)) != NULL) { 758 pushstring(ap->val, strlen(ap->val), ap); 759 checkkwd = savecheckkwd; 760 goto top; 761 } 762 } 763out: 764 checkkwd = (t == TNOT) ? savecheckkwd : 0; 765 } 766#ifdef DEBUG 767 if (!alreadyseen) 768 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 769 else 770 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 771#endif 772 return (t); 773} 774 775 776/* 777 * Read the next input token. 778 * If the token is a word, we set backquotelist to the list of cmds in 779 * backquotes. We set quoteflag to true if any part of the word was 780 * quoted. 781 * If the token is TREDIR, then we set redirnode to a structure containing 782 * the redirection. 783 * In all cases, the variable startlinno is set to the number of the line 784 * on which the token starts. 785 * 786 * [Change comment: here documents and internal procedures] 787 * [Readtoken shouldn't have any arguments. Perhaps we should make the 788 * word parsing code into a separate routine. In this case, readtoken 789 * doesn't need to have any internal procedures, but parseword does. 790 * We could also make parseoperator in essence the main routine, and 791 * have parseword (readtoken1?) handle both words and redirection.] 792 */ 793 794#define RETURN(token) return lasttoken = token 795 796STATIC int 797xxreadtoken(void) 798{ 799 int c; 800 801 if (tokpushback) { 802 tokpushback = 0; 803 return lasttoken; 804 } 805 if (needprompt) { 806 setprompt(2); 807 needprompt = 0; 808 } 809 startlinno = plinno; 810 for (;;) { /* until token or start of word found */ 811 c = pgetc_macro(); 812 if (c == ' ' || c == '\t') 813 continue; /* quick check for white space first */ 814 switch (c) { 815 case ' ': case '\t': 816 continue; 817 case '#': 818 while ((c = pgetc()) != '\n' && c != PEOF); 819 pungetc(); 820 continue; 821 case '\\': 822 if (pgetc() == '\n') { 823 startlinno = ++plinno; 824 if (doprompt) 825 setprompt(2); 826 else 827 setprompt(0); 828 continue; 829 } 830 pungetc(); 831 goto breakloop; 832 case '\n': 833 plinno++; 834 needprompt = doprompt; 835 RETURN(TNL); 836 case PEOF: 837 RETURN(TEOF); 838 case '&': 839 if (pgetc() == '&') 840 RETURN(TAND); 841 pungetc(); 842 RETURN(TBACKGND); 843 case '|': 844 if (pgetc() == '|') 845 RETURN(TOR); 846 pungetc(); 847 RETURN(TPIPE); 848 case ';': 849 if (pgetc() == ';') 850 RETURN(TENDCASE); 851 pungetc(); 852 RETURN(TSEMI); 853 case '(': 854 RETURN(TLP); 855 case ')': 856 RETURN(TRP); 857 default: 858 goto breakloop; 859 } 860 } 861breakloop: 862 return readtoken1(c, BASESYNTAX, (char *)NULL, 0); 863#undef RETURN 864} 865 866 867 868/* 869 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 870 * is not NULL, read a here document. In the latter case, eofmark is the 871 * word which marks the end of the document and striptabs is true if 872 * leading tabs should be stripped from the document. The argument firstc 873 * is the first character of the input token or document. 874 * 875 * Because C does not have internal subroutines, I have simulated them 876 * using goto's to implement the subroutine linkage. The following macros 877 * will run code that appears at the end of readtoken1. 878 */ 879 880#define CHECKEND() {goto checkend; checkend_return:;} 881#define PARSEREDIR() {goto parseredir; parseredir_return:;} 882#define PARSESUB() {goto parsesub; parsesub_return:;} 883#define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;} 884#define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;} 885#define PARSEARITH() {goto parsearith; parsearith_return:;} 886 887STATIC int 888readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs) 889{ 890 int c = firstc; 891 char *out; 892 int len; 893 char line[EOFMARKLEN + 1]; 894 struct nodelist *bqlist; 895 int quotef; 896 int dblquote; 897 int varnest; /* levels of variables expansion */ 898 int arinest; /* levels of arithmetic expansion */ 899 int parenlevel; /* levels of parens in arithmetic */ 900 int oldstyle; 901 char const *prevsyntax; /* syntax before arithmetic */ 902 int synentry; 903#if __GNUC__ 904 /* Avoid longjmp clobbering */ 905 (void) &out; 906 (void) "ef; 907 (void) &dblquote; 908 (void) &varnest; 909 (void) &arinest; 910 (void) &parenlevel; 911 (void) &oldstyle; 912 (void) &prevsyntax; 913 (void) &syntax; 914 (void) &synentry; 915#endif 916 917 startlinno = plinno; 918 dblquote = 0; 919 if (syntax == DQSYNTAX) 920 dblquote = 1; 921 quotef = 0; 922 bqlist = NULL; 923 varnest = 0; 924 arinest = 0; 925 parenlevel = 0; 926 927 STARTSTACKSTR(out); 928 loop: { /* for each line, until end of word */ 929#if ATTY 930 if (c == '\034' && doprompt 931 && attyset() && ! equal(termval(), "emacs")) { 932 attyline(); 933 if (syntax == BASESYNTAX) 934 return readtoken(); 935 c = pgetc(); 936 goto loop; 937 } 938#endif 939 CHECKEND(); /* set c to PEOF if at end of here document */ 940 for (;;) { /* until end of line or end of word */ 941 CHECKSTRSPACE(3, out); /* permit 3 calls to USTPUTC */ 942 943 synentry = syntax[c]; 944 945 switch(synentry) { 946 case CNL: /* '\n' */ 947 if (syntax == BASESYNTAX) 948 goto endword; /* exit outer loop */ 949 USTPUTC(c, out); 950 plinno++; 951 if (doprompt) 952 setprompt(2); 953 else 954 setprompt(0); 955 c = pgetc(); 956 goto loop; /* continue outer loop */ 957 case CWORD: 958 USTPUTC(c, out); 959 break; 960 case CCTL: 961 if (eofmark == NULL || dblquote) 962 USTPUTC(CTLESC, out); 963 USTPUTC(c, out); 964 break; 965 case CBACK: /* backslash */ 966 c = pgetc(); 967 if (c == PEOF) { 968 USTPUTC('\\', out); 969 pungetc(); 970 } else if (c == '\n') { 971 if (doprompt) 972 setprompt(2); 973 else 974 setprompt(0); 975 } else { 976 if (dblquote && c != '\\' && 977 c != '`' && c != '$' && 978 (c != '"' || eofmark != NULL)) 979 USTPUTC('\\', out); 980 if (SQSYNTAX[c] == CCTL) 981 USTPUTC(CTLESC, out); 982 else if (eofmark == NULL) 983 USTPUTC(CTLQUOTEMARK, out); 984 USTPUTC(c, out); 985 quotef++; 986 } 987 break; 988 case CSQUOTE: 989 if (eofmark == NULL) 990 USTPUTC(CTLQUOTEMARK, out); 991 syntax = SQSYNTAX; 992 break; 993 case CDQUOTE: 994 if (eofmark == NULL) 995 USTPUTC(CTLQUOTEMARK, out); 996 syntax = DQSYNTAX; 997 dblquote = 1; 998 break; 999 case CENDQUOTE: 1000 if (eofmark != NULL && arinest == 0 && 1001 varnest == 0) { 1002 USTPUTC(c, out); 1003 } else { 1004 if (arinest) { 1005 syntax = ARISYNTAX; 1006 dblquote = 0; 1007 } else if (eofmark == NULL) { 1008 syntax = BASESYNTAX; 1009 dblquote = 0; 1010 } 1011 quotef++; 1012 } 1013 break; 1014 case CVAR: /* '$' */ 1015 PARSESUB(); /* parse substitution */ 1016 break; 1017 case CENDVAR: /* '}' */ 1018 if (varnest > 0) { 1019 varnest--; 1020 USTPUTC(CTLENDVAR, out); 1021 } else { 1022 USTPUTC(c, out); 1023 } 1024 break; 1025 case CLP: /* '(' in arithmetic */ 1026 parenlevel++; 1027 USTPUTC(c, out); 1028 break; 1029 case CRP: /* ')' in arithmetic */ 1030 if (parenlevel > 0) { 1031 USTPUTC(c, out); 1032 --parenlevel; 1033 } else { 1034 if (pgetc() == ')') { 1035 if (--arinest == 0) { 1036 USTPUTC(CTLENDARI, out); 1037 syntax = prevsyntax; 1038 if (syntax == DQSYNTAX) 1039 dblquote = 1; 1040 else 1041 dblquote = 0; 1042 } else 1043 USTPUTC(')', out); 1044 } else { 1045 /* 1046 * unbalanced parens 1047 * (don't 2nd guess - no error) 1048 */ 1049 pungetc(); 1050 USTPUTC(')', out); 1051 } 1052 } 1053 break; 1054 case CBQUOTE: /* '`' */ 1055 PARSEBACKQOLD(); 1056 break; 1057 case CEOF: 1058 goto endword; /* exit outer loop */ 1059 default: 1060 if (varnest == 0) 1061 goto endword; /* exit outer loop */ 1062 USTPUTC(c, out); 1063 } 1064 c = pgetc_macro(); 1065 } 1066 } 1067endword: 1068 if (syntax == ARISYNTAX) 1069 synerror("Missing '))'"); 1070 if (syntax != BASESYNTAX && ! parsebackquote && eofmark == NULL) 1071 synerror("Unterminated quoted string"); 1072 if (varnest != 0) { 1073 startlinno = plinno; 1074 synerror("Missing '}'"); 1075 } 1076 USTPUTC('\0', out); 1077 len = out - stackblock(); 1078 out = stackblock(); 1079 if (eofmark == NULL) { 1080 if ((c == '>' || c == '<') 1081 && quotef == 0 1082 && len <= 2 1083 && (*out == '\0' || is_digit(*out))) { 1084 PARSEREDIR(); 1085 return lasttoken = TREDIR; 1086 } else { 1087 pungetc(); 1088 } 1089 } 1090 quoteflag = quotef; 1091 backquotelist = bqlist; 1092 grabstackblock(len); 1093 wordtext = out; 1094 return lasttoken = TWORD; 1095/* end of readtoken routine */ 1096 1097 1098 1099/* 1100 * Check to see whether we are at the end of the here document. When this 1101 * is called, c is set to the first character of the next input line. If 1102 * we are at the end of the here document, this routine sets the c to PEOF. 1103 */ 1104 1105checkend: { 1106 if (eofmark) { 1107 if (striptabs) { 1108 while (c == '\t') 1109 c = pgetc(); 1110 } 1111 if (c == *eofmark) { 1112 if (pfgets(line, sizeof line) != NULL) { 1113 char *p, *q; 1114 1115 p = line; 1116 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++); 1117 if (*p == '\n' && *q == '\0') { 1118 c = PEOF; 1119 plinno++; 1120 needprompt = doprompt; 1121 } else { 1122 pushstring(line, strlen(line), NULL); 1123 } 1124 } 1125 } 1126 } 1127 goto checkend_return; 1128} 1129 1130 1131/* 1132 * Parse a redirection operator. The variable "out" points to a string 1133 * specifying the fd to be redirected. The variable "c" contains the 1134 * first character of the redirection operator. 1135 */ 1136 1137parseredir: { 1138 char fd = *out; 1139 union node *np; 1140 1141 np = (union node *)stalloc(sizeof (struct nfile)); 1142 if (c == '>') { 1143 np->nfile.fd = 1; 1144 c = pgetc(); 1145 if (c == '>') 1146 np->type = NAPPEND; 1147 else if (c == '&') 1148 np->type = NTOFD; 1149 else if (c == '|') 1150 np->type = NCLOBBER; 1151 else { 1152 np->type = NTO; 1153 pungetc(); 1154 } 1155 } else { /* c == '<' */ 1156 np->nfile.fd = 0; 1157 c = pgetc(); 1158 if (c == '<') { 1159 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1160 np = (union node *)stalloc(sizeof (struct nhere)); 1161 np->nfile.fd = 0; 1162 } 1163 np->type = NHERE; 1164 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1165 heredoc->here = np; 1166 if ((c = pgetc()) == '-') { 1167 heredoc->striptabs = 1; 1168 } else { 1169 heredoc->striptabs = 0; 1170 pungetc(); 1171 } 1172 } else if (c == '&') 1173 np->type = NFROMFD; 1174 else if (c == '>') 1175 np->type = NFROMTO; 1176 else { 1177 np->type = NFROM; 1178 pungetc(); 1179 } 1180 } 1181 if (fd != '\0') 1182 np->nfile.fd = digit_val(fd); 1183 redirnode = np; 1184 goto parseredir_return; 1185} 1186 1187 1188/* 1189 * Parse a substitution. At this point, we have read the dollar sign 1190 * and nothing else. 1191 */ 1192 1193parsesub: { 1194 int subtype; 1195 int typeloc; 1196 int flags; 1197 char *p; 1198#ifndef GDB_HACK 1199 static const char types[] = "}-+?="; 1200#endif 1201 int bracketed_name = 0; /* used to handle ${[0-9]*} variables */ 1202 1203 c = pgetc(); 1204 if (c != '(' && c != '{' && !is_name(c) && !is_special(c)) { 1205 USTPUTC('$', out); 1206 pungetc(); 1207 } else if (c == '(') { /* $(command) or $((arith)) */ 1208 if (pgetc() == '(') { 1209 PARSEARITH(); 1210 } else { 1211 pungetc(); 1212 PARSEBACKQNEW(); 1213 } 1214 } else { 1215 USTPUTC(CTLVAR, out); 1216 typeloc = out - stackblock(); 1217 USTPUTC(VSNORMAL, out); 1218 subtype = VSNORMAL; 1219 if (c == '{') { 1220 bracketed_name = 1; 1221 c = pgetc(); 1222 if (c == '#') { 1223 if ((c = pgetc()) == '}') 1224 c = '#'; 1225 else 1226 subtype = VSLENGTH; 1227 } 1228 else 1229 subtype = 0; 1230 } 1231 if (is_name(c)) { 1232 do { 1233 STPUTC(c, out); 1234 c = pgetc(); 1235 } while (is_in_name(c)); 1236 } else if (is_digit(c)) { 1237 if (bracketed_name) { 1238 do { 1239 STPUTC(c, out); 1240 c = pgetc(); 1241 } while (is_digit(c)); 1242 } else { 1243 STPUTC(c, out); 1244 c = pgetc(); 1245 } 1246 } else { 1247 if (! is_special(c)) 1248badsub: synerror("Bad substitution"); 1249 USTPUTC(c, out); 1250 c = pgetc(); 1251 } 1252 STPUTC('=', out); 1253 flags = 0; 1254 if (subtype == 0) { 1255 switch (c) { 1256 case ':': 1257 flags = VSNUL; 1258 c = pgetc(); 1259 /*FALLTHROUGH*/ 1260 default: 1261 p = strchr(types, c); 1262 if (p == NULL) 1263 goto badsub; 1264 subtype = p - types + VSNORMAL; 1265 break; 1266 case '%': 1267 case '#': 1268 { 1269 int cc = c; 1270 subtype = c == '#' ? VSTRIMLEFT : 1271 VSTRIMRIGHT; 1272 c = pgetc(); 1273 if (c == cc) 1274 subtype++; 1275 else 1276 pungetc(); 1277 break; 1278 } 1279 } 1280 } else { 1281 pungetc(); 1282 } 1283 if (subtype != VSLENGTH && (dblquote || arinest)) 1284 flags |= VSQUOTE; 1285 *(stackblock() + typeloc) = subtype | flags; 1286 if (subtype != VSNORMAL) 1287 varnest++; 1288 } 1289 goto parsesub_return; 1290} 1291 1292 1293/* 1294 * Called to parse command substitutions. Newstyle is set if the command 1295 * is enclosed inside $(...); nlpp is a pointer to the head of the linked 1296 * list of commands (passed by reference), and savelen is the number of 1297 * characters on the top of the stack which must be preserved. 1298 */ 1299 1300parsebackq: { 1301 struct nodelist **nlpp; 1302 int savepbq; 1303 union node *n; 1304 char *volatile str; 1305 struct jmploc jmploc; 1306 struct jmploc *volatile savehandler; 1307 int savelen; 1308 int saveprompt; 1309#if __GNUC__ 1310 /* Avoid longjmp clobbering */ 1311 (void) &saveprompt; 1312#endif 1313 1314 savepbq = parsebackquote; 1315 if (setjmp(jmploc.loc)) { 1316 if (str) 1317 ckfree(str); 1318 parsebackquote = 0; 1319 handler = savehandler; 1320 longjmp(handler->loc, 1); 1321 } 1322 INTOFF; 1323 str = NULL; 1324 savelen = out - stackblock(); 1325 if (savelen > 0) { 1326 str = ckmalloc(savelen); 1327 memcpy(str, stackblock(), savelen); 1328 } 1329 savehandler = handler; 1330 handler = &jmploc; 1331 INTON; 1332 if (oldstyle) { 1333 /* We must read until the closing backquote, giving special 1334 treatment to some slashes, and then push the string and 1335 reread it as input, interpreting it normally. */ 1336 char *out; 1337 int c; 1338 int savelen; 1339 char *str; 1340 1341 1342 STARTSTACKSTR(out); 1343 for (;;) { 1344 if (needprompt) { 1345 setprompt(2); 1346 needprompt = 0; 1347 } 1348 switch (c = pgetc()) { 1349 case '`': 1350 goto done; 1351 1352 case '\\': 1353 if ((c = pgetc()) == '\n') { 1354 plinno++; 1355 if (doprompt) 1356 setprompt(2); 1357 else 1358 setprompt(0); 1359 /* 1360 * If eating a newline, avoid putting 1361 * the newline into the new character 1362 * stream (via the STPUTC after the 1363 * switch). 1364 */ 1365 continue; 1366 } 1367 if (c != '\\' && c != '`' && c != '$' 1368 && (!dblquote || c != '"')) 1369 STPUTC('\\', out); 1370 break; 1371 1372 case '\n': 1373 plinno++; 1374 needprompt = doprompt; 1375 break; 1376 1377 case PEOF: 1378 startlinno = plinno; 1379 synerror("EOF in backquote substitution"); 1380 break; 1381 1382 default: 1383 break; 1384 } 1385 STPUTC(c, out); 1386 } 1387done: 1388 STPUTC('\0', out); 1389 savelen = out - stackblock(); 1390 if (savelen > 0) { 1391 str = ckmalloc(savelen); 1392 memcpy(str, stackblock(), savelen); 1393 setinputstring(str, 1); 1394 } 1395 } 1396 nlpp = &bqlist; 1397 while (*nlpp) 1398 nlpp = &(*nlpp)->next; 1399 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1400 (*nlpp)->next = NULL; 1401 parsebackquote = oldstyle; 1402 1403 if (oldstyle) { 1404 saveprompt = doprompt; 1405 doprompt = 0; 1406 } 1407 1408 n = list(0); 1409 1410 if (oldstyle) 1411 doprompt = saveprompt; 1412 else { 1413 if (readtoken() != TRP) 1414 synexpect(TRP); 1415 } 1416 1417 (*nlpp)->n = n; 1418 if (oldstyle) { 1419 /* 1420 * Start reading from old file again, ignoring any pushed back 1421 * tokens left from the backquote parsing 1422 */ 1423 popfile(); 1424 tokpushback = 0; 1425 } 1426 while (stackblocksize() <= savelen) 1427 growstackblock(); 1428 STARTSTACKSTR(out); 1429 if (str) { 1430 memcpy(out, str, savelen); 1431 STADJUST(savelen, out); 1432 INTOFF; 1433 ckfree(str); 1434 str = NULL; 1435 INTON; 1436 } 1437 parsebackquote = savepbq; 1438 handler = savehandler; 1439 if (arinest || dblquote) 1440 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1441 else 1442 USTPUTC(CTLBACKQ, out); 1443 if (oldstyle) 1444 goto parsebackq_oldreturn; 1445 else 1446 goto parsebackq_newreturn; 1447} 1448 1449/* 1450 * Parse an arithmetic expansion (indicate start of one and set state) 1451 */ 1452parsearith: { 1453 1454 if (++arinest == 1) { 1455 prevsyntax = syntax; 1456 syntax = ARISYNTAX; 1457 USTPUTC(CTLARI, out); 1458 if (dblquote) 1459 USTPUTC('"',out); 1460 else 1461 USTPUTC(' ',out); 1462 } else { 1463 /* 1464 * we collapse embedded arithmetic expansion to 1465 * parenthesis, which should be equivalent 1466 */ 1467 USTPUTC('(', out); 1468 } 1469 goto parsearith_return; 1470} 1471 1472} /* end of readtoken */ 1473 1474 1475 1476#ifdef mkinit 1477RESET { 1478 tokpushback = 0; 1479 checkkwd = 0; 1480} 1481#endif 1482 1483/* 1484 * Returns true if the text contains nothing to expand (no dollar signs 1485 * or backquotes). 1486 */ 1487 1488STATIC int 1489noexpand(char *text) 1490{ 1491 char *p; 1492 char c; 1493 1494 p = text; 1495 while ((c = *p++) != '\0') { 1496 if ( c == CTLQUOTEMARK) 1497 continue; 1498 if (c == CTLESC) 1499 p++; 1500 else if (BASESYNTAX[(int)c] == CCTL) 1501 return 0; 1502 } 1503 return 1; 1504} 1505 1506 1507/* 1508 * Return true if the argument is a legal variable name (a letter or 1509 * underscore followed by zero or more letters, underscores, and digits). 1510 */ 1511 1512int 1513goodname(char *name) 1514{ 1515 char *p; 1516 1517 p = name; 1518 if (! is_name(*p)) 1519 return 0; 1520 while (*++p) { 1521 if (! is_in_name(*p)) 1522 return 0; 1523 } 1524 return 1; 1525} 1526 1527 1528/* 1529 * Called when an unexpected token is read during the parse. The argument 1530 * is the token that is expected, or -1 if more than one type of token can 1531 * occur at this point. 1532 */ 1533 1534STATIC void 1535synexpect(int token) 1536{ 1537 char msg[64]; 1538 1539 if (token >= 0) { 1540 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1541 tokname[lasttoken], tokname[token]); 1542 } else { 1543 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1544 } 1545 synerror(msg); 1546} 1547 1548 1549STATIC void 1550synerror(char *msg) 1551{ 1552 if (commandname) 1553 outfmt(&errout, "%s: %d: ", commandname, startlinno); 1554 outfmt(&errout, "Syntax error: %s\n", msg); 1555 error((char *)NULL); 1556} 1557 1558STATIC void 1559setprompt(int which) 1560{ 1561 whichprompt = which; 1562 1563#ifndef NO_HISTORY 1564 if (!el) 1565#endif 1566 out2str(getprompt(NULL)); 1567} 1568 1569/* 1570 * called by editline -- any expansions to the prompt 1571 * should be added here. 1572 */ 1573char * 1574getprompt(void *unused __unused) 1575{ 1576 switch (whichprompt) { 1577 case 0: 1578 return ""; 1579 case 1: 1580 return ps1val(); 1581 case 2: 1582 return ps2val(); 1583 default: 1584 return "<internal prompt error>"; 1585 } 1586} 1587