/*- * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Kenneth Almquist. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef lint #if 0 static char sccsid[] = "@(#)parser.c 8.7 (Berkeley) 5/16/95"; #endif #endif /* not lint */ #include __FBSDID("$FreeBSD$"); #include #include #include #include "shell.h" #include "parser.h" #include "nodes.h" #include "expand.h" /* defines rmescapes() */ #include "syntax.h" #include "options.h" #include "input.h" #include "output.h" #include "var.h" #include "error.h" #include "memalloc.h" #include "mystring.h" #include "alias.h" #include "show.h" #include "eval.h" #include "exec.h" /* to check for special builtins */ #ifndef NO_HISTORY #include "myhistedit.h" #endif /* * Shell command parser. */ #define PROMPTLEN 128 /* values of checkkwd variable */ #define CHKALIAS 0x1 #define CHKKWD 0x2 #define CHKNL 0x4 /* values returned by readtoken */ #include "token.h" struct heredoc { struct heredoc *next; /* next here document in list */ union node *here; /* redirection node */ char *eofmark; /* string indicating end of input */ int striptabs; /* if set, strip leading tabs */ }; struct parser_temp { struct parser_temp *next; void *data; }; static struct heredoc *heredoclist; /* list of here documents to read */ static int doprompt; /* if set, prompt the user */ static int needprompt; /* true if interactive and at start of line */ static int lasttoken; /* last token read */ static int tokpushback; /* last token pushed back */ static char *wordtext; /* text of last word returned by readtoken */ static int checkkwd; static struct nodelist *backquotelist; static union node *redirnode; static struct heredoc *heredoc; static int quoteflag; /* set if (part of) last token was quoted */ static int startlinno; /* line # where last token started */ static int funclinno; /* line # where the current function started */ static struct parser_temp *parser_temp; static union node *list(int); static union node *andor(void); static union node *pipeline(void); static union node *command(void); static union node *simplecmd(union node **, union node *); static union node *makename(void); static union node *makebinary(int type, union node *n1, union node *n2); static void parsefname(void); static void parseheredoc(void); static int peektoken(void); static int readtoken(void); static int xxreadtoken(void); static int readtoken1(int, const char *, const char *, int); static int noexpand(char *); static void consumetoken(int); static void synexpect(int) __dead2; static void synerror(const char *) __dead2; static void setprompt(int); static void * parser_temp_alloc(size_t len) { struct parser_temp *t; INTOFF; t = ckmalloc(sizeof(*t)); t->data = NULL; t->next = parser_temp; parser_temp = t; t->data = ckmalloc(len); INTON; return t->data; } static void * parser_temp_realloc(void *ptr, size_t len) { struct parser_temp *t; INTOFF; t = parser_temp; if (ptr != t->data) error("bug: parser_temp_realloc misused"); t->data = ckrealloc(t->data, len); INTON; return t->data; } static void parser_temp_free_upto(void *ptr) { struct parser_temp *t; int done = 0; INTOFF; while (parser_temp != NULL && !done) { t = parser_temp; parser_temp = t->next; done = t->data == ptr; ckfree(t->data); ckfree(t); } INTON; if (!done) error("bug: parser_temp_free_upto misused"); } static void parser_temp_free_all(void) { struct parser_temp *t; INTOFF; while (parser_temp != NULL) { t = parser_temp; parser_temp = t->next; ckfree(t->data); ckfree(t); } INTON; } /* * Read and parse a command. Returns NEOF on end of file. (NULL is a * valid parse tree indicating a blank line.) */ union node * parsecmd(int interact) { int t; /* This assumes the parser is not re-entered, * which could happen if we add command substitution on PS1/PS2. */ parser_temp_free_all(); heredoclist = NULL; tokpushback = 0; checkkwd = 0; doprompt = interact; if (doprompt) setprompt(1); else setprompt(0); needprompt = 0; t = readtoken(); if (t == TEOF) return NEOF; if (t == TNL) return NULL; tokpushback++; return list(1); } static union node * list(int nlflag) { union node *ntop, *n1, *n2, *n3; int tok; checkkwd = CHKNL | CHKKWD | CHKALIAS; if (!nlflag && tokendlist[peektoken()]) return NULL; ntop = n1 = NULL; for (;;) { n2 = andor(); tok = readtoken(); if (tok == TBACKGND) { if (n2 != NULL && n2->type == NPIPE) { n2->npipe.backgnd = 1; } else if (n2 != NULL && n2->type == NREDIR) { n2->type = NBACKGND; } else { n3 = (union node *)stalloc(sizeof (struct nredir)); n3->type = NBACKGND; n3->nredir.n = n2; n3->nredir.redirect = NULL; n2 = n3; } } if (ntop == NULL) ntop = n2; else if (n1 == NULL) { n1 = makebinary(NSEMI, ntop, n2); ntop = n1; } else { n3 = makebinary(NSEMI, n1->nbinary.ch2, n2); n1->nbinary.ch2 = n3; n1 = n3; } switch (tok) { case TBACKGND: case TSEMI: tok = readtoken(); /* FALLTHROUGH */ case TNL: if (tok == TNL) { parseheredoc(); if (nlflag) return ntop; } else if (tok == TEOF && nlflag) { parseheredoc(); return ntop; } else { tokpushback++; } checkkwd = CHKNL | CHKKWD | CHKALIAS; if (!nlflag && tokendlist[peektoken()]) return ntop; break; case TEOF: if (heredoclist) parseheredoc(); else pungetc(); /* push back EOF on input */ return ntop; default: if (nlflag) synexpect(-1); tokpushback++; return ntop; } } } static union node * andor(void) { union node *n; int t; n = pipeline(); for (;;) { if ((t = readtoken()) == TAND) { t = NAND; } else if (t == TOR) { t = NOR; } else { tokpushback++; return n; } n = makebinary(t, n, pipeline()); } } static union node * pipeline(void) { union node *n1, *n2, *pipenode; struct nodelist *lp, *prev; int negate, t; negate = 0; checkkwd = CHKNL | CHKKWD | CHKALIAS; TRACE(("pipeline: entered\n")); while (readtoken() == TNOT) negate = !negate; tokpushback++; n1 = command(); if (readtoken() == TPIPE) { pipenode = (union node *)stalloc(sizeof (struct npipe)); pipenode->type = NPIPE; pipenode->npipe.backgnd = 0; lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); pipenode->npipe.cmdlist = lp; lp->n = n1; do { prev = lp; lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); checkkwd = CHKNL | CHKKWD | CHKALIAS; t = readtoken(); tokpushback++; if (t == TNOT) lp->n = pipeline(); else lp->n = command(); prev->next = lp; } while (readtoken() == TPIPE); lp->next = NULL; n1 = pipenode; } tokpushback++; if (negate) { n2 = (union node *)stalloc(sizeof (struct nnot)); n2->type = NNOT; n2->nnot.com = n1; return n2; } else return n1; } static union node * command(void) { union node *n1, *n2; union node *ap, **app; union node *cp, **cpp; union node *redir, **rpp; int t; int is_subshell; checkkwd = CHKNL | CHKKWD | CHKALIAS; is_subshell = 0; redir = NULL; n1 = NULL; rpp = &redir; /* Check for redirection which may precede command */ while (readtoken() == TREDIR) { *rpp = n2 = redirnode; rpp = &n2->nfile.next; parsefname(); } tokpushback++; switch (readtoken()) { case TIF: n1 = (union node *)stalloc(sizeof (struct nif)); n1->type = NIF; if ((n1->nif.test = list(0)) == NULL) synexpect(-1); consumetoken(TTHEN); n1->nif.ifpart = list(0); n2 = n1; while (readtoken() == TELIF) { n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); n2 = n2->nif.elsepart; n2->type = NIF; if ((n2->nif.test = list(0)) == NULL) synexpect(-1); consumetoken(TTHEN); n2->nif.ifpart = list(0); } if (lasttoken == TELSE) n2->nif.elsepart = list(0); else { n2->nif.elsepart = NULL; tokpushback++; } consumetoken(TFI); checkkwd = CHKKWD | CHKALIAS; break; case TWHILE: case TUNTIL: t = lasttoken; if ((n1 = list(0)) == NULL) synexpect(-1); consumetoken(TDO); n1 = makebinary((t == TWHILE)? NWHILE : NUNTIL, n1, list(0)); consumetoken(TDONE); checkkwd = CHKKWD | CHKALIAS; break; case TFOR: if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) synerror("Bad for loop variable"); n1 = (union node *)stalloc(sizeof (struct nfor)); n1->type = NFOR; n1->nfor.var = wordtext; while (readtoken() == TNL) ; if (lasttoken == TWORD && ! quoteflag && equal(wordtext, "in")) { app = ≈ while (readtoken() == TWORD) { n2 = makename(); *app = n2; app = &n2->narg.next; } *app = NULL; n1->nfor.args = ap; if (lasttoken != TNL && lasttoken != TSEMI) synexpect(-1); } else { static char argvars[5] = { CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0' }; n2 = (union node *)stalloc(sizeof (struct narg)); n2->type = NARG; n2->narg.text = argvars; n2->narg.backquote = NULL; n2->narg.next = NULL; n1->nfor.args = n2; /* * Newline or semicolon here is optional (but note * that the original Bourne shell only allowed NL). */ if (lasttoken != TNL && lasttoken != TSEMI) tokpushback++; } checkkwd = CHKNL | CHKKWD | CHKALIAS; if ((t = readtoken()) == TDO) t = TDONE; else if (t == TBEGIN) t = TEND; else synexpect(-1); n1->nfor.body = list(0); consumetoken(t); checkkwd = CHKKWD | CHKALIAS; break; case TCASE: n1 = (union node *)stalloc(sizeof (struct ncase)); n1->type = NCASE; consumetoken(TWORD); n1->ncase.expr = makename(); while (readtoken() == TNL); if (lasttoken != TWORD || ! equal(wordtext, "in")) synerror("expecting \"in\""); cpp = &n1->ncase.cases; checkkwd = CHKNL | CHKKWD, readtoken(); while (lasttoken != TESAC) { *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); cp->type = NCLIST; app = &cp->nclist.pattern; if (lasttoken == TLP) readtoken(); for (;;) { *app = ap = makename(); checkkwd = CHKNL | CHKKWD; if (readtoken() != TPIPE) break; app = &ap->narg.next; readtoken(); } ap->narg.next = NULL; if (lasttoken != TRP) synexpect(TRP); cp->nclist.body = list(0); checkkwd = CHKNL | CHKKWD | CHKALIAS; if ((t = readtoken()) != TESAC) { if (t == TENDCASE) ; else if (t == TFALLTHRU) cp->type = NCLISTFALLTHRU; else synexpect(TENDCASE); checkkwd = CHKNL | CHKKWD, readtoken(); } cpp = &cp->nclist.next; } *cpp = NULL; checkkwd = CHKKWD | CHKALIAS; break; case TLP: n1 = (union node *)stalloc(sizeof (struct nredir)); n1->type = NSUBSHELL; n1->nredir.n = list(0); n1->nredir.redirect = NULL; consumetoken(TRP); checkkwd = CHKKWD | CHKALIAS; is_subshell = 1; break; case TBEGIN: n1 = list(0); consumetoken(TEND); checkkwd = CHKKWD | CHKALIAS; break; /* A simple command must have at least one redirection or word. */ case TBACKGND: case TSEMI: case TAND: case TOR: case TPIPE: case TENDCASE: case TFALLTHRU: case TEOF: case TNL: case TRP: if (!redir) synexpect(-1); case TWORD: tokpushback++; n1 = simplecmd(rpp, redir); return n1; default: synexpect(-1); } /* Now check for redirection which may follow command */ while (readtoken() == TREDIR) { *rpp = n2 = redirnode; rpp = &n2->nfile.next; parsefname(); } tokpushback++; *rpp = NULL; if (redir) { if (!is_subshell) { n2 = (union node *)stalloc(sizeof (struct nredir)); n2->type = NREDIR; n2->nredir.n = n1; n1 = n2; } n1->nredir.redirect = redir; } return n1; } static union node * simplecmd(union node **rpp, union node *redir) { union node *args, **app; union node **orig_rpp = rpp; union node *n = NULL; int special; int savecheckkwd; /* If we don't have any redirections already, then we must reset */ /* rpp to be the address of the local redir variable. */ if (redir == 0) rpp = &redir; args = NULL; app = &args; /* * We save the incoming value, because we need this for shell * functions. There can not be a redirect or an argument between * the function name and the open parenthesis. */ orig_rpp = rpp; savecheckkwd = CHKALIAS; for (;;) { checkkwd = savecheckkwd; if (readtoken() == TWORD) { n = makename(); *app = n; app = &n->narg.next; if (savecheckkwd != 0 && !isassignment(wordtext)) savecheckkwd = 0; } else if (lasttoken == TREDIR) { *rpp = n = redirnode; rpp = &n->nfile.next; parsefname(); /* read name of redirection file */ } else if (lasttoken == TLP && app == &args->narg.next && rpp == orig_rpp) { /* We have a function */ consumetoken(TRP); funclinno = plinno; /* * - Require plain text. * - Functions with '/' cannot be called. * - Reject name=(). * - Reject ksh extended glob patterns. */ if (!noexpand(n->narg.text) || quoteflag || strchr(n->narg.text, '/') || strchr("!%*+-=?@}~", n->narg.text[strlen(n->narg.text) - 1])) synerror("Bad function name"); rmescapes(n->narg.text); if (find_builtin(n->narg.text, &special) >= 0 && special) synerror("Cannot override a special builtin with a function"); n->type = NDEFUN; n->narg.next = command(); funclinno = 0; return n; } else { tokpushback++; break; } } *app = NULL; *rpp = NULL; n = (union node *)stalloc(sizeof (struct ncmd)); n->type = NCMD; n->ncmd.args = args; n->ncmd.redirect = redir; return n; } static union node * makename(void) { union node *n; n = (union node *)stalloc(sizeof (struct narg)); n->type = NARG; n->narg.next = NULL; n->narg.text = wordtext; n->narg.backquote = backquotelist; return n; } static union node * makebinary(int type, union node *n1, union node *n2) { union node *n; n = (union node *)stalloc(sizeof (struct nbinary)); n->type = type; n->nbinary.ch1 = n1; n->nbinary.ch2 = n2; return (n); } void forcealias(void) { checkkwd |= CHKALIAS; } void fixredir(union node *n, const char *text, int err) { TRACE(("Fix redir %s %d\n", text, err)); if (!err) n->ndup.vname = NULL; if (is_digit(text[0]) && text[1] == '\0') n->ndup.dupfd = digit_val(text[0]); else if (text[0] == '-' && text[1] == '\0') n->ndup.dupfd = -1; else { if (err) synerror("Bad fd number"); else n->ndup.vname = makename(); } } static void parsefname(void) { union node *n = redirnode; consumetoken(TWORD); if (n->type == NHERE) { struct heredoc *here = heredoc; struct heredoc *p; if (quoteflag == 0) n->type = NXHERE; TRACE(("Here document %d\n", n->type)); if (here->striptabs) { while (*wordtext == '\t') wordtext++; } if (! noexpand(wordtext)) synerror("Illegal eof marker for << redirection"); rmescapes(wordtext); here->eofmark = wordtext; here->next = NULL; if (heredoclist == NULL) heredoclist = here; else { for (p = heredoclist ; p->next ; p = p->next); p->next = here; } } else if (n->type == NTOFD || n->type == NFROMFD) { fixredir(n, wordtext, 0); } else { n->nfile.fname = makename(); } } /* * Input any here documents. */ static void parseheredoc(void) { struct heredoc *here; union node *n; while (heredoclist) { here = heredoclist; heredoclist = here->next; if (needprompt) { setprompt(2); needprompt = 0; } readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, here->eofmark, here->striptabs); n = makename(); here->here->nhere.doc = n; } } static int peektoken(void) { int t; t = readtoken(); tokpushback++; return (t); } static int readtoken(void) { int t; struct alias *ap; #ifdef DEBUG int alreadyseen = tokpushback; #endif top: t = xxreadtoken(); /* * eat newlines */ if (checkkwd & CHKNL) { while (t == TNL) { parseheredoc(); t = xxreadtoken(); } } /* * check for keywords and aliases */ if (t == TWORD && !quoteflag) { const char * const *pp; if (checkkwd & CHKKWD) for (pp = parsekwd; *pp; pp++) { if (**pp == *wordtext && equal(*pp, wordtext)) { lasttoken = t = pp - parsekwd + KWDOFFSET; TRACE(("keyword %s recognized\n", tokname[t])); goto out; } } if (checkkwd & CHKALIAS && (ap = lookupalias(wordtext, 1)) != NULL) { pushstring(ap->val, strlen(ap->val), ap); goto top; } } out: if (t != TNOT) checkkwd = 0; #ifdef DEBUG if (!alreadyseen) TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); else TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); #endif return (t); } /* * Read the next input token. * If the token is a word, we set backquotelist to the list of cmds in * backquotes. We set quoteflag to true if any part of the word was * quoted. * If the token is TREDIR, then we set redirnode to a structure containing * the redirection. * In all cases, the variable startlinno is set to the number of the line * on which the token starts. * * [Change comment: here documents and internal procedures] * [Readtoken shouldn't have any arguments. Perhaps we should make the * word parsing code into a separate routine. In this case, readtoken * doesn't need to have any internal procedures, but parseword does. * We could also make parseoperator in essence the main routine, and * have parseword (readtoken1?) handle both words and redirection.] */ #define RETURN(token) return lasttoken = token static int xxreadtoken(void) { int c; if (tokpushback) { tokpushback = 0; return lasttoken; } if (needprompt) { setprompt(2); needprompt = 0; } startlinno = plinno; for (;;) { /* until token or start of word found */ c = pgetc_macro(); switch (c) { case ' ': case '\t': continue; case '#': while ((c = pgetc()) != '\n' && c != PEOF); pungetc(); continue; case '\\': if (pgetc() == '\n') { startlinno = ++plinno; if (doprompt) setprompt(2); else setprompt(0); continue; } pungetc(); goto breakloop; case '\n': plinno++; needprompt = doprompt; RETURN(TNL); case PEOF: RETURN(TEOF); case '&': if (pgetc() == '&') RETURN(TAND); pungetc(); RETURN(TBACKGND); case '|': if (pgetc() == '|') RETURN(TOR); pungetc(); RETURN(TPIPE); case ';': c = pgetc(); if (c == ';') RETURN(TENDCASE); else if (c == '&') RETURN(TFALLTHRU); pungetc(); RETURN(TSEMI); case '(': RETURN(TLP); case ')': RETURN(TRP); default: goto breakloop; } } breakloop: return readtoken1(c, BASESYNTAX, (char *)NULL, 0); #undef RETURN } #define MAXNEST_static 8 struct tokenstate { const char *syntax; /* *SYNTAX */ int parenlevel; /* levels of parentheses in arithmetic */ enum tokenstate_category { TSTATE_TOP, TSTATE_VAR_OLD, /* ${var+-=?}, inherits dquotes */ TSTATE_VAR_NEW, /* other ${var...}, own dquote state */ TSTATE_ARITH } category; }; /* * Check to see whether we are at the end of the here document. When this * is called, c is set to the first character of the next input line. If * we are at the end of the here document, this routine sets the c to PEOF. * The new value of c is returned. */ static int checkend(int c, const char *eofmark, int striptabs) { if (striptabs) { while (c == '\t') c = pgetc(); } if (c == *eofmark) { int c2; const char *q; for (q = eofmark + 1; c2 = pgetc(), *q != '\0' && c2 == *q; q++) ; if ((c2 == PEOF || c2 == '\n') && *q == '\0') { c = PEOF; if (c2 == '\n') { plinno++; needprompt = doprompt; } } else { pungetc(); pushstring(eofmark + 1, q - (eofmark + 1), NULL); } } return (c); } /* * Called to parse command substitutions. */ static char * parsebackq(char *out, struct nodelist **pbqlist, int oldstyle, int dblquote, int quoted) { struct nodelist **nlpp; union node *n; char *volatile str; struct jmploc jmploc; struct jmploc *const savehandler = handler; size_t savelen; int saveprompt; const int bq_startlinno = plinno; char *volatile ostr = NULL; struct parsefile *const savetopfile = getcurrentfile(); struct heredoc *const saveheredoclist = heredoclist; struct heredoc *here; str = NULL; if (setjmp(jmploc.loc)) { popfilesupto(savetopfile); if (str) ckfree(str); if (ostr) ckfree(ostr); heredoclist = saveheredoclist; handler = savehandler; if (exception == EXERROR) { startlinno = bq_startlinno; synerror("Error in command substitution"); } longjmp(handler->loc, 1); } INTOFF; savelen = out - stackblock(); if (savelen > 0) { str = ckmalloc(savelen); memcpy(str, stackblock(), savelen); } handler = &jmploc; heredoclist = NULL; INTON; if (oldstyle) { /* We must read until the closing backquote, giving special treatment to some slashes, and then push the string and reread it as input, interpreting it normally. */ char *oout; int c; int olen; STARTSTACKSTR(oout); for (;;) { if (needprompt) { setprompt(2); needprompt = 0; } CHECKSTRSPACE(2, oout); switch (c = pgetc()) { case '`': goto done; case '\\': if ((c = pgetc()) == '\n') { plinno++; if (doprompt) setprompt(2); else setprompt(0); /* * If eating a newline, avoid putting * the newline into the new character * stream (via the USTPUTC after the * switch). */ continue; } if (c != '\\' && c != '`' && c != '$' && (!dblquote || c != '"')) USTPUTC('\\', oout); break; case '\n': plinno++; needprompt = doprompt; break; case PEOF: startlinno = plinno; synerror("EOF in backquote substitution"); break; default: break; } USTPUTC(c, oout); } done: USTPUTC('\0', oout); olen = oout - stackblock(); INTOFF; ostr = ckmalloc(olen); memcpy(ostr, stackblock(), olen); setinputstring(ostr, 1); INTON; } nlpp = pbqlist; while (*nlpp) nlpp = &(*nlpp)->next; *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); (*nlpp)->next = NULL; if (oldstyle) { saveprompt = doprompt; doprompt = 0; } n = list(0); if (oldstyle) { if (peektoken() != TEOF) synexpect(-1); doprompt = saveprompt; } else consumetoken(TRP); (*nlpp)->n = n; if (oldstyle) { /* * Start reading from old file again, ignoring any pushed back * tokens left from the backquote parsing */ popfile(); tokpushback = 0; } STARTSTACKSTR(out); CHECKSTRSPACE(savelen + 1, out); INTOFF; if (str) { memcpy(out, str, savelen); STADJUST(savelen, out); ckfree(str); str = NULL; } if (ostr) { ckfree(ostr); ostr = NULL; } here = saveheredoclist; if (here != NULL) { while (here->next != NULL) here = here->next; here->next = heredoclist; heredoclist = saveheredoclist; } handler = savehandler; INTON; if (quoted) USTPUTC(CTLBACKQ | CTLQUOTE, out); else USTPUTC(CTLBACKQ, out); return out; } /* * Called to parse a backslash escape sequence inside $'...'. * The backslash has already been read. */ static char * readcstyleesc(char *out) { int c, v, i, n; c = pgetc(); switch (c) { case '\0': synerror("Unterminated quoted string"); case '\n': plinno++; if (doprompt) setprompt(2); else setprompt(0); return out; case '\\': case '\'': case '"': v = c; break; case 'a': v = '\a'; break; case 'b': v = '\b'; break; case 'e': v = '\033'; break; case 'f': v = '\f'; break; case 'n': v = '\n'; break; case 'r': v = '\r'; break; case 't': v = '\t'; break; case 'v': v = '\v'; break; case 'x': v = 0; for (;;) { c = pgetc(); if (c >= '0' && c <= '9') v = (v << 4) + c - '0'; else if (c >= 'A' && c <= 'F') v = (v << 4) + c - 'A' + 10; else if (c >= 'a' && c <= 'f') v = (v << 4) + c - 'a' + 10; else break; } pungetc(); break; case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': v = c - '0'; c = pgetc(); if (c >= '0' && c <= '7') { v <<= 3; v += c - '0'; c = pgetc(); if (c >= '0' && c <= '7') { v <<= 3; v += c - '0'; } else pungetc(); } else pungetc(); break; case 'c': c = pgetc(); if (c < 0x3f || c > 0x7a || c == 0x60) synerror("Bad escape sequence"); if (c == '\\' && pgetc() != '\\') synerror("Bad escape sequence"); if (c == '?') v = 127; else v = c & 0x1f; break; case 'u': case 'U': n = c == 'U' ? 8 : 4; v = 0; for (i = 0; i < n; i++) { c = pgetc(); if (c >= '0' && c <= '9') v = (v << 4) + c - '0'; else if (c >= 'A' && c <= 'F') v = (v << 4) + c - 'A' + 10; else if (c >= 'a' && c <= 'f') v = (v << 4) + c - 'a' + 10; else synerror("Bad escape sequence"); } if (v == 0 || (v >= 0xd800 && v <= 0xdfff)) synerror("Bad escape sequence"); /* We really need iconv here. */ if (initial_localeisutf8 && v > 127) { CHECKSTRSPACE(4, out); /* * We cannot use wctomb() as the locale may have * changed. */ if (v <= 0x7ff) { USTPUTC(0xc0 | v >> 6, out); USTPUTC(0x80 | (v & 0x3f), out); return out; } else if (v <= 0xffff) { USTPUTC(0xe0 | v >> 12, out); USTPUTC(0x80 | ((v >> 6) & 0x3f), out); USTPUTC(0x80 | (v & 0x3f), out); return out; } else if (v <= 0x10ffff) { USTPUTC(0xf0 | v >> 18, out); USTPUTC(0x80 | ((v >> 12) & 0x3f), out); USTPUTC(0x80 | ((v >> 6) & 0x3f), out); USTPUTC(0x80 | (v & 0x3f), out); return out; } } if (v > 127) v = '?'; break; default: synerror("Bad escape sequence"); } v = (char)v; /* * We can't handle NUL bytes. * POSIX says we should skip till the closing quote. */ if (v == '\0') { while ((c = pgetc()) != '\'') { if (c == '\\') c = pgetc(); if (c == PEOF) synerror("Unterminated quoted string"); if (c == '\n') { plinno++; if (doprompt) setprompt(2); else setprompt(0); } } pungetc(); return out; } if (SQSYNTAX[v] == CCTL) USTPUTC(CTLESC, out); USTPUTC(v, out); return out; } /* * If eofmark is NULL, read a word or a redirection symbol. If eofmark * is not NULL, read a here document. In the latter case, eofmark is the * word which marks the end of the document and striptabs is true if * leading tabs should be stripped from the document. The argument firstc * is the first character of the input token or document. * * Because C does not have internal subroutines, I have simulated them * using goto's to implement the subroutine linkage. The following macros * will run code that appears at the end of readtoken1. */ #define PARSEREDIR() {goto parseredir; parseredir_return:;} #define PARSESUB() {goto parsesub; parsesub_return:;} #define PARSEARITH() {goto parsearith; parsearith_return:;} static int readtoken1(int firstc, char const *initialsyntax, const char *eofmark, int striptabs) { int c = firstc; char *out; int len; struct nodelist *bqlist; int quotef; int newvarnest; int level; int synentry; struct tokenstate state_static[MAXNEST_static]; int maxnest = MAXNEST_static; struct tokenstate *state = state_static; int sqiscstyle = 0; startlinno = plinno; quotef = 0; bqlist = NULL; newvarnest = 0; level = 0; state[level].syntax = initialsyntax; state[level].parenlevel = 0; state[level].category = TSTATE_TOP; STARTSTACKSTR(out); loop: { /* for each line, until end of word */ if (eofmark) /* set c to PEOF if at end of here document */ c = checkend(c, eofmark, striptabs); for (;;) { /* until end of line or end of word */ CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */ synentry = state[level].syntax[c]; switch(synentry) { case CNL: /* '\n' */ if (state[level].syntax == BASESYNTAX) goto endword; /* exit outer loop */ USTPUTC(c, out); plinno++; if (doprompt) setprompt(2); else setprompt(0); c = pgetc(); goto loop; /* continue outer loop */ case CSBACK: if (sqiscstyle) { out = readcstyleesc(out); break; } /* FALLTHROUGH */ case CWORD: USTPUTC(c, out); break; case CCTL: if (eofmark == NULL || initialsyntax != SQSYNTAX) USTPUTC(CTLESC, out); USTPUTC(c, out); break; case CBACK: /* backslash */ c = pgetc(); if (c == PEOF) { USTPUTC('\\', out); pungetc(); } else if (c == '\n') { plinno++; if (doprompt) setprompt(2); else setprompt(0); } else { if (state[level].syntax == DQSYNTAX && c != '\\' && c != '`' && c != '$' && (c != '"' || (eofmark != NULL && newvarnest == 0)) && (c != '}' || state[level].category != TSTATE_VAR_OLD)) USTPUTC('\\', out); if ((eofmark == NULL || newvarnest > 0) && state[level].syntax == BASESYNTAX) USTPUTC(CTLQUOTEMARK, out); if (SQSYNTAX[c] == CCTL) USTPUTC(CTLESC, out); USTPUTC(c, out); if ((eofmark == NULL || newvarnest > 0) && state[level].syntax == BASESYNTAX && state[level].category == TSTATE_VAR_OLD) USTPUTC(CTLQUOTEEND, out); quotef++; } break; case CSQUOTE: USTPUTC(CTLQUOTEMARK, out); state[level].syntax = SQSYNTAX; sqiscstyle = 0; break; case CDQUOTE: USTPUTC(CTLQUOTEMARK, out); state[level].syntax = DQSYNTAX; break; case CENDQUOTE: if (eofmark != NULL && newvarnest == 0) USTPUTC(c, out); else { if (state[level].category == TSTATE_VAR_OLD) USTPUTC(CTLQUOTEEND, out); state[level].syntax = BASESYNTAX; quotef++; } break; case CVAR: /* '$' */ PARSESUB(); /* parse substitution */ break; case CENDVAR: /* '}' */ if (level > 0 && ((state[level].category == TSTATE_VAR_OLD && state[level].syntax == state[level - 1].syntax) || (state[level].category == TSTATE_VAR_NEW && state[level].syntax == BASESYNTAX))) { if (state[level].category == TSTATE_VAR_NEW) newvarnest--; level--; USTPUTC(CTLENDVAR, out); } else { USTPUTC(c, out); } break; case CLP: /* '(' in arithmetic */ state[level].parenlevel++; USTPUTC(c, out); break; case CRP: /* ')' in arithmetic */ if (state[level].parenlevel > 0) { USTPUTC(c, out); --state[level].parenlevel; } else { if (pgetc() == ')') { if (level > 0 && state[level].category == TSTATE_ARITH) { level--; USTPUTC(CTLENDARI, out); } else USTPUTC(')', out); } else { /* * unbalanced parens * (don't 2nd guess - no error) */ pungetc(); USTPUTC(')', out); } } break; case CBQUOTE: /* '`' */ out = parsebackq(out, &bqlist, 1, state[level].syntax == DQSYNTAX && (eofmark == NULL || newvarnest > 0), state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX); break; case CEOF: goto endword; /* exit outer loop */ case CIGN: break; default: if (level == 0) goto endword; /* exit outer loop */ USTPUTC(c, out); } c = pgetc_macro(); } } endword: if (state[level].syntax == ARISYNTAX) synerror("Missing '))'"); if (state[level].syntax != BASESYNTAX && eofmark == NULL) synerror("Unterminated quoted string"); if (state[level].category == TSTATE_VAR_OLD || state[level].category == TSTATE_VAR_NEW) { startlinno = plinno; synerror("Missing '}'"); } if (state != state_static) parser_temp_free_upto(state); USTPUTC('\0', out); len = out - stackblock(); out = stackblock(); if (eofmark == NULL) { if ((c == '>' || c == '<') && quotef == 0 && len <= 2 && (*out == '\0' || is_digit(*out))) { PARSEREDIR(); return lasttoken = TREDIR; } else { pungetc(); } } quoteflag = quotef; backquotelist = bqlist; grabstackblock(len); wordtext = out; return lasttoken = TWORD; /* end of readtoken routine */ /* * Parse a redirection operator. The variable "out" points to a string * specifying the fd to be redirected. The variable "c" contains the * first character of the redirection operator. */ parseredir: { char fd = *out; union node *np; np = (union node *)stalloc(sizeof (struct nfile)); if (c == '>') { np->nfile.fd = 1; c = pgetc(); if (c == '>') np->type = NAPPEND; else if (c == '&') np->type = NTOFD; else if (c == '|') np->type = NCLOBBER; else { np->type = NTO; pungetc(); } } else { /* c == '<' */ np->nfile.fd = 0; c = pgetc(); if (c == '<') { if (sizeof (struct nfile) != sizeof (struct nhere)) { np = (union node *)stalloc(sizeof (struct nhere)); np->nfile.fd = 0; } np->type = NHERE; heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); heredoc->here = np; if ((c = pgetc()) == '-') { heredoc->striptabs = 1; } else { heredoc->striptabs = 0; pungetc(); } } else if (c == '&') np->type = NFROMFD; else if (c == '>') np->type = NFROMTO; else { np->type = NFROM; pungetc(); } } if (fd != '\0') np->nfile.fd = digit_val(fd); redirnode = np; goto parseredir_return; } /* * Parse a substitution. At this point, we have read the dollar sign * and nothing else. */ parsesub: { char buf[10]; int subtype; int typeloc; int flags; char *p; static const char types[] = "}-+?="; int bracketed_name = 0; /* used to handle ${[0-9]*} variables */ int linno; int length; int c1; c = pgetc(); if (c == '(') { /* $(command) or $((arith)) */ if (pgetc() == '(') { PARSEARITH(); } else { pungetc(); out = parsebackq(out, &bqlist, 0, state[level].syntax == DQSYNTAX && (eofmark == NULL || newvarnest > 0), state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX); } } else if (c == '{' || is_name(c) || is_special(c)) { USTPUTC(CTLVAR, out); typeloc = out - stackblock(); USTPUTC(VSNORMAL, out); subtype = VSNORMAL; flags = 0; if (c == '{') { bracketed_name = 1; c = pgetc(); subtype = 0; } varname: if (!is_eof(c) && is_name(c)) { length = 0; do { STPUTC(c, out); c = pgetc(); length++; } while (!is_eof(c) && is_in_name(c)); if (length == 6 && strncmp(out - length, "LINENO", length) == 0) { /* Replace the variable name with the * current line number. */ linno = plinno; if (funclinno != 0) linno -= funclinno - 1; snprintf(buf, sizeof(buf), "%d", linno); STADJUST(-6, out); STPUTS(buf, out); flags |= VSLINENO; } } else if (is_digit(c)) { if (bracketed_name) { do { STPUTC(c, out); c = pgetc(); } while (is_digit(c)); } else { STPUTC(c, out); c = pgetc(); } } else if (is_special(c)) { c1 = c; c = pgetc(); if (subtype == 0 && c1 == '#') { subtype = VSLENGTH; if (strchr(types, c) == NULL && c != ':' && c != '#' && c != '%') goto varname; c1 = c; c = pgetc(); if (c1 != '}' && c == '}') { pungetc(); c = c1; goto varname; } pungetc(); c = c1; c1 = '#'; subtype = 0; } USTPUTC(c1, out); } else { subtype = VSERROR; if (c == '}') pungetc(); else if (c == '\n' || c == PEOF) synerror("Unexpected end of line in substitution"); else USTPUTC(c, out); } if (subtype == 0) { switch (c) { case ':': flags |= VSNUL; c = pgetc(); /*FALLTHROUGH*/ default: p = strchr(types, c); if (p == NULL) { if (c == '\n' || c == PEOF) synerror("Unexpected end of line in substitution"); if (flags == VSNUL) STPUTC(':', out); STPUTC(c, out); subtype = VSERROR; } else subtype = p - types + VSNORMAL; break; case '%': case '#': { int cc = c; subtype = c == '#' ? VSTRIMLEFT : VSTRIMRIGHT; c = pgetc(); if (c == cc) subtype++; else pungetc(); break; } } } else if (subtype != VSERROR) { if (subtype == VSLENGTH && c != '}') subtype = VSERROR; pungetc(); } STPUTC('=', out); if (state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX) flags |= VSQUOTE; *(stackblock() + typeloc) = subtype | flags; if (subtype != VSNORMAL) { if (level + 1 >= maxnest) { maxnest *= 2; if (state == state_static) { state = parser_temp_alloc( maxnest * sizeof(*state)); memcpy(state, state_static, MAXNEST_static * sizeof(*state)); } else state = parser_temp_realloc(state, maxnest * sizeof(*state)); } level++; state[level].parenlevel = 0; if (subtype == VSMINUS || subtype == VSPLUS || subtype == VSQUESTION || subtype == VSASSIGN) { /* * For operators that were in the Bourne shell, * inherit the double-quote state. */ state[level].syntax = state[level - 1].syntax; state[level].category = TSTATE_VAR_OLD; } else { /* * The other operators take a pattern, * so go to BASESYNTAX. * Also, ' and " are now special, even * in here documents. */ state[level].syntax = BASESYNTAX; state[level].category = TSTATE_VAR_NEW; newvarnest++; } } } else if (c == '\'' && state[level].syntax == BASESYNTAX) { /* $'cstylequotes' */ USTPUTC(CTLQUOTEMARK, out); state[level].syntax = SQSYNTAX; sqiscstyle = 1; } else { USTPUTC('$', out); pungetc(); } goto parsesub_return; } /* * Parse an arithmetic expansion (indicate start of one and set state) */ parsearith: { if (level + 1 >= maxnest) { maxnest *= 2; if (state == state_static) { state = parser_temp_alloc( maxnest * sizeof(*state)); memcpy(state, state_static, MAXNEST_static * sizeof(*state)); } else state = parser_temp_realloc(state, maxnest * sizeof(*state)); } level++; state[level].syntax = ARISYNTAX; state[level].parenlevel = 0; state[level].category = TSTATE_ARITH; USTPUTC(CTLARI, out); if (state[level - 1].syntax == DQSYNTAX) USTPUTC('"',out); else USTPUTC(' ',out); goto parsearith_return; } } /* end of readtoken */ /* * Returns true if the text contains nothing to expand (no dollar signs * or backquotes). */ static int noexpand(char *text) { char *p; char c; p = text; while ((c = *p++) != '\0') { if ( c == CTLQUOTEMARK) continue; if (c == CTLESC) p++; else if (BASESYNTAX[(int)c] == CCTL) return 0; } return 1; } /* * Return true if the argument is a legal variable name (a letter or * underscore followed by zero or more letters, underscores, and digits). */ int goodname(const char *name) { const char *p; p = name; if (! is_name(*p)) return 0; while (*++p) { if (! is_in_name(*p)) return 0; } return 1; } int isassignment(const char *p) { if (!is_name(*p)) return 0; p++; for (;;) { if (*p == '=') return 1; else if (!is_in_name(*p)) return 0; p++; } } static void consumetoken(int token) { if (readtoken() != token) synexpect(token); } /* * Called when an unexpected token is read during the parse. The argument * is the token that is expected, or -1 if more than one type of token can * occur at this point. */ static void synexpect(int token) { char msg[64]; if (token >= 0) { fmtstr(msg, 64, "%s unexpected (expecting %s)", tokname[lasttoken], tokname[token]); } else { fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); } synerror(msg); } static void synerror(const char *msg) { if (commandname) outfmt(out2, "%s: %d: ", commandname, startlinno); outfmt(out2, "Syntax error: %s\n", msg); error((char *)NULL); } static void setprompt(int which) { whichprompt = which; #ifndef NO_HISTORY if (!el) #endif { out2str(getprompt(NULL)); flushout(out2); } } /* * called by editline -- any expansions to the prompt * should be added here. */ char * getprompt(void *unused __unused) { static char ps[PROMPTLEN]; const char *fmt; const char *pwd; int i, trim; static char internal_error[] = "??"; /* * Select prompt format. */ switch (whichprompt) { case 0: fmt = nullstr; break; case 1: fmt = ps1val(); break; case 2: fmt = ps2val(); break; default: return internal_error; } /* * Format prompt string. */ for (i = 0; (i < 127) && (*fmt != '\0'); i++, fmt++) if (*fmt == '\\') switch (*++fmt) { /* * Hostname. * * \h specifies just the local hostname, * \H specifies fully-qualified hostname. */ case 'h': case 'H': ps[i] = '\0'; gethostname(&ps[i], PROMPTLEN - i); /* Skip to end of hostname. */ trim = (*fmt == 'h') ? '.' : '\0'; while ((ps[i+1] != '\0') && (ps[i+1] != trim)) i++; break; /* * Working directory. * * \W specifies just the final component, * \w specifies the entire path. */ case 'W': case 'w': pwd = lookupvar("PWD"); if (pwd == NULL) pwd = "?"; if (*fmt == 'W' && *pwd == '/' && pwd[1] != '\0') strlcpy(&ps[i], strrchr(pwd, '/') + 1, PROMPTLEN - i); else strlcpy(&ps[i], pwd, PROMPTLEN - i); /* Skip to end of path. */ while (ps[i + 1] != '\0') i++; break; /* * Superuser status. * * '$' for normal users, '#' for root. */ case '$': ps[i] = (geteuid() != 0) ? '$' : '#'; break; /* * A literal \. */ case '\\': ps[i] = '\\'; break; /* * Emit unrecognized formats verbatim. */ default: ps[i++] = '\\'; ps[i] = *fmt; break; } else ps[i] = *fmt; ps[i] = '\0'; return (ps); } const char * expandstr(const char *ps) { union node n; struct jmploc jmploc; struct jmploc *const savehandler = handler; const int saveprompt = doprompt; struct parsefile *const savetopfile = getcurrentfile(); struct parser_temp *const saveparser_temp = parser_temp; const char *result = NULL; if (!setjmp(jmploc.loc)) { handler = &jmploc; parser_temp = NULL; setinputstring(ps, 1); doprompt = 0; readtoken1(pgetc(), DQSYNTAX, "", 0); if (backquotelist != NULL) error("Command substitution not allowed here"); n.narg.type = NARG; n.narg.next = NULL; n.narg.text = wordtext; n.narg.backquote = backquotelist; expandarg(&n, NULL, 0); result = stackblock(); INTOFF; } handler = savehandler; doprompt = saveprompt; popfilesupto(savetopfile); if (parser_temp != saveparser_temp) { parser_temp_free_all(); parser_temp = saveparser_temp; } if (result != NULL) { INTON; } else if (exception == EXINT) raise(SIGINT); return result; }