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freebsd/bin/sh/parser.c
Edward Tomasz Napierala d81ca439e7 Make sh(1) support \u in PS1. This removes one fork/exec on interactive 
shell startup.

Reviewed by:	0mp (man page), jilles
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D18790
2019-01-24 11:59:46 +00:00

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/*-
* 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("$FreeBSD$");
#include <sys/param.h>
#include <pwd.h>
#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 getusername(char *, size_t);
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 = &ap;
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);
}
static struct passwd *
getpwlogin(void)
{
const char *login;
login = getlogin();
if (login == NULL)
return (NULL);
return (getpwnam(login));
}
static void
getusername(char *name, size_t namelen)
{
static char cached_name[MAXLOGNAME];
struct passwd *pw;
uid_t euid;
if (cached_name[0] == '\0') {
euid = geteuid();
/*
* Handle the case when there is more than one
* login with the same UID, or when the login
* returned by getlogin(2) does no longer match
* the current UID.
*/
pw = getpwlogin();
if (pw == NULL || pw->pw_uid != euid)
pw = getpwuid(euid);
if (pw != NULL) {
strlcpy(cached_name, pw->pw_name,
sizeof(cached_name));
} else {
snprintf(cached_name, sizeof(cached_name),
"%u", euid);
}
}
strlcpy(name, cached_name, namelen);
}
/*
* 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 *home;
const char *pwd;
size_t homelen;
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;
/*
* User name.
*/
case 'u':
ps[i] = '\0';
getusername(&ps[i], PROMPTLEN - i);
/* Skip to end of username. */
while (ps[i + 1] != '\0')
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 {
home = lookupvar("HOME");
if (home != NULL)
homelen = strlen(home);
if (home != NULL &&
strcmp(home, "/") != 0 &&
strncmp(pwd, home, homelen) == 0 &&
(pwd[homelen] == '/' ||
pwd[homelen] == '\0')) {
strlcpy(&ps[i], "~",
PROMPTLEN - i);
strlcpy(&ps[i + 1],
pwd + homelen,
PROMPTLEN - i - 1);
} 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;
}
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