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Diffstat (limited to '')
| -rw-r--r-- | bin/1sh/parser.c | 2122 |
1 files changed, 2122 insertions, 0 deletions
diff --git a/bin/1sh/parser.c b/bin/1sh/parser.c new file mode 100644 index 00000000..97d6f52a --- /dev/null +++ b/bin/1sh/parser.c @@ -0,0 +1,2122 @@ +/*- + * SPDX-License-Identifier: BSD-3-Clause + * + * 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. + * 3. 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 <sys/cdefs.h> +__FBSDID("$FreeBSD: releng/12.1/bin/sh/parser.c 334008 2018-05-21 21:52:48Z jilles $"); + +#include <stdlib.h> +#include <unistd.h> +#include <stdio.h> + +#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; + +#define NOEOFMARK ((const char *)&heredoclist) + + +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 int pgetc_linecont(void); + + +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); +} + + +/* + * Read and parse words for wordexp. + * Returns a list of NARG nodes; NULL if there are no words. + */ +union node * +parsewordexp(void) +{ + union node *n, *first = NULL, **pnext; + 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 = 0; + setprompt(0); + needprompt = 0; + pnext = &first; + while ((t = readtoken()) != TEOF) { + if (t != TWORD) + synexpect(TWORD); + n = makename(); + *pnext = n; + pnext = &n->narg.next; + } + return first; +} + + +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 == NULL) + 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(); + /* FALLTHROUGH */ + default: + return readtoken1(c, BASESYNTAX, (char *)NULL, 0); + case '\n': + plinno++; + needprompt = doprompt; + RETURN(TNL); + case PEOF: + RETURN(TEOF); + case '&': + if (pgetc_linecont() == '&') + RETURN(TAND); + pungetc(); + RETURN(TBACKGND); + case '|': + if (pgetc_linecont() == '|') + RETURN(TOR); + pungetc(); + RETURN(TPIPE); + case ';': + c = pgetc_linecont(); + if (c == ';') + RETURN(TENDCASE); + else if (c == '&') + RETURN(TFALLTHRU); + pungetc(); + RETURN(TSEMI); + case '(': + RETURN(TLP); + case ')': + RETURN(TRP); + } + } +#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); + } + } else if (c == '\n' && *eofmark == '\0') { + c = PEOF; + plinno++; + needprompt = doprompt; + } + return (c); +} + + +/* + * 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. + */ + +static void +parseredir(char *out, int c) +{ + char fd = *out; + union node *np; + + np = (union node *)stalloc(sizeof (struct nfile)); + if (c == '>') { + np->nfile.fd = 1; + c = pgetc_linecont(); + 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_linecont(); + 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_linecont()) == '-') { + 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; +} + +/* + * 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); + c = pgetc_linecont(); + if (c == '`') + break; + switch (c) { + case '\\': + c = pgetc(); + 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); + } + 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, vc, i, n; + unsigned int v; + + 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"); + } + vc = (char)v; + /* + * We can't handle NUL bytes. + * POSIX says we should skip till the closing quote. + */ + if (vc == '\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[vc] == CCTL) + USTPUTC(CTLESC, out); + USTPUTC(vc, 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 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 && eofmark != NOEOFMARK) + /* 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 (level == 0) + goto endword; /* exit outer loop */ + /* FALLTHROUGH */ + case CQNL: + 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_linecont() == ')') { + 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(out, c); + return lasttoken = TREDIR; + } else { + pungetc(); + } + } + quoteflag = quotef; + backquotelist = bqlist; + grabstackblock(len); + wordtext = out; + return lasttoken = TWORD; +/* end of readtoken routine */ + + +/* + * Parse a substitution. At this point, we have read the dollar sign + * and nothing else. + */ + +parsesub: { + int subtype; + int typeloc; + int flags; + char *p; + static const char types[] = "}-+?="; + int linno; + int length; + int c1; + + c = pgetc_linecont(); + if (c == '(') { /* $(command) or $((arith)) */ + if (pgetc_linecont() == '(') { + 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 == '{') { + c = pgetc_linecont(); + subtype = 0; + } +varname: + if (!is_eof(c) && is_name(c)) { + length = 0; + do { + STPUTC(c, out); + c = pgetc_linecont(); + 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. */ + STADJUST(-6, out); + CHECKSTRSPACE(11, out); + linno = plinno; + if (funclinno != 0) + linno -= funclinno - 1; + length = snprintf(out, 11, "%d", linno); + if (length > 10) + length = 10; + out += length; + flags |= VSLINENO; + } + } else if (is_digit(c)) { + if (subtype != VSNORMAL) { + do { + STPUTC(c, out); + c = pgetc_linecont(); + } while (is_digit(c)); + } else { + USTPUTC(c, out); + c = pgetc_linecont(); + } + } else if (is_special(c)) { + c1 = c; + c = pgetc_linecont(); + if (subtype == 0 && c1 == '#') { + subtype = VSLENGTH; + if (strchr(types, c) == NULL && c != ':' && + c != '#' && c != '%') + goto varname; + c1 = c; + c = pgetc_linecont(); + 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 if (BASESYNTAX[c] != CCTL) + USTPUTC(c, out); + } + if (subtype == 0) { + switch (c) { + case ':': + flags |= VSNUL; + c = pgetc_linecont(); + /*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); + if (BASESYNTAX[c] != CCTL) + STPUTC(c, out); + subtype = VSERROR; + } else + subtype = p - types + VSNORMAL; + break; + case '%': + case '#': + { + int cc = c; + subtype = c == '#' ? VSTRIMLEFT : + VSTRIMRIGHT; + c = pgetc_linecont(); + 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); + else if (arg0) + outfmt(out2, "%s: ", arg0); + outfmt(out2, "Syntax error: %s\n", msg); + error((char *)NULL); +} + +static void +setprompt(int which) +{ + whichprompt = which; + if (which == 0) + return; + +#ifndef NO_HISTORY + if (!el) +#endif + { + out2str(getprompt(NULL)); + flushout(out2); + } +} + +static int +pgetc_linecont(void) +{ + int c; + + while ((c = pgetc_macro()) == '\\') { + c = pgetc(); + if (c == '\n') { + plinno++; + if (doprompt) + setprompt(2); + else + setprompt(0); + } else { + pungetc(); + /* Allow the backslash to be pushed back. */ + pushstring("\\", 1, NULL); + return (pgetc()); + } + } + return (c); +} + +/* + * 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 = ""; + break; + case 1: + fmt = ps1val(); + break; + case 2: + fmt = ps2val(); + break; + default: + return internal_error; + } + + /* + * Format prompt string. + */ + for (i = 0; (i < PROMPTLEN - 1) && (*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 - 1); + ps[PROMPTLEN - 1] = '\0'; + /* Skip to end of hostname. */ + trim = (*fmt == 'h') ? '.' : '\0'; + while ((ps[i] != '\0') && (ps[i] != trim)) + i++; + --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 == '\0') + 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] = '\\'; + if (i < PROMPTLEN - 2) + 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, NOEOFMARK, 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; +} |