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freebsd-nq/bin/sh/expand.c
Ralf S. Engelschall f7d95a075c Various small code cleanups resulting from a code reviewing 
and linting procedure:

1. Remove useless sub-expression:

   - if (*start || (!ifsspc && start > string && (nulonly || 1))) {
   + if (*start || (!ifsspc && start > string)) {

   The sub-expression "(nulonly || 1)" always evaluates to true and
   according to CVS logs seems to be just a left-over from some
   debugging and introduced by accident. Removing the sub-expression
   doesn't change semantics and a code inspection showed that the
   variable "nulonly" is also not necessary here in any way (and the
   expression would require fixing instead of removing).

2. Remove dead code:

   -                if (backslash && c == '\\') {
   -                        if (read(STDIN_FILENO, &c, 1) != 1) {
   -                                status = 1;
   -                                break;
   -                        }
   -                        STPUTC(c, p);
   -                } else if (ap[1] != NULL && strchr(ifs, c) != NULL) {
   +                if (ap[1] != NULL && strchr(ifs, c) != NULL) {

   Inspection of the control and data flow showed that variable
   "backslash" is always false (0) when the "if"-expression is
   evaluated, hence the whole block is effectively dead code.
   Additionally, the skipping of characters after a backslash is already
   performed correctly a few lines above, so this code is also not
   needed at all. According to the CVS logs and the ASH 0.2 sources,
   this code existed in this way already since its early days.

3. Cleanup Style:

   - ! trap[signo][0] == '\0' &&
   + ! (trap[signo][0] == '\0') &&

   The expression wants to ensure the trap is not assigned the empty
   string. But the "!" operator has higher precedence than "==", so the
   comparison should be put into parenthesis to form the intended way of
   expression. Nevertheless the code was effectively not really broken
   as both particular NUL comparisons are semantically equal, of course.
   But the parenthesized version is a lot more intuitive.

4. Remove shadowing variable declaration:

   - char *q;

   The declaration of symbol "q" hides another identical declaration of
   "q" in the same context. As the other "q" is already reused multiple
   times and also can be reused again without negative side-effects,
   just remove the shadowing declaration.

5. Just small cosmetics:

   - if (ifsset() != 0)
   + if (ifsset())

   The ifsset() macro is already coded by returning the boolean result
   of a comparison operator, so no need to compare this boolean result
   again against a numerical value. This also aligns the macros usage to
   the remaining existing code.

Reviewed by: stefanf@
2005-09-06 19:30:00 +00:00

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/*-
* 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[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95";
#endif
#endif /* not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <errno.h>
#include <dirent.h>
#include <unistd.h>
#include <pwd.h>
#include <stdlib.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
/*
* Routines to expand arguments to commands. We have to deal with
* backquotes, shell variables, and file metacharacters.
*/
#include "shell.h"
#include "main.h"
#include "nodes.h"
#include "eval.h"
#include "expand.h"
#include "syntax.h"
#include "parser.h"
#include "jobs.h"
#include "options.h"
#include "var.h"
#include "input.h"
#include "output.h"
#include "memalloc.h"
#include "error.h"
#include "mystring.h"
#include "arith.h"
#include "show.h"
/*
* Structure specifying which parts of the string should be searched
* for IFS characters.
*/
struct ifsregion {
struct ifsregion *next; /* next region in list */
int begoff; /* offset of start of region */
int endoff; /* offset of end of region */
int nulonly; /* search for nul bytes only */
};
STATIC char *expdest; /* output of current string */
STATIC struct nodelist *argbackq; /* list of back quote expressions */
STATIC struct ifsregion ifsfirst; /* first struct in list of ifs regions */
STATIC struct ifsregion *ifslastp; /* last struct in list */
STATIC struct arglist exparg; /* holds expanded arg list */
STATIC void argstr(char *, int);
STATIC char *exptilde(char *, int);
STATIC void expbackq(union node *, int, int);
STATIC int subevalvar(char *, char *, int, int, int, int);
STATIC char *evalvar(char *, int);
STATIC int varisset(char *, int);
STATIC void varvalue(char *, int, int);
STATIC void recordregion(int, int, int);
STATIC void removerecordregions(int);
STATIC void ifsbreakup(char *, struct arglist *);
STATIC void expandmeta(struct strlist *, int);
STATIC void expmeta(char *, char *);
STATIC void addfname(char *);
STATIC struct strlist *expsort(struct strlist *);
STATIC struct strlist *msort(struct strlist *, int);
STATIC int pmatch(char *, char *, int);
STATIC char *cvtnum(int, char *);
STATIC int collate_range_cmp(int, int);
STATIC int
collate_range_cmp(int c1, int c2)
{
static char s1[2], s2[2];
s1[0] = c1;
s2[0] = c2;
return (strcoll(s1, s2));
}
/*
* Expand shell variables and backquotes inside a here document.
* union node *arg the document
* int fd; where to write the expanded version
*/
void
expandhere(union node *arg, int fd)
{
herefd = fd;
expandarg(arg, (struct arglist *)NULL, 0);
xwrite(fd, stackblock(), expdest - stackblock());
}
/*
* Perform variable substitution and command substitution on an argument,
* placing the resulting list of arguments in arglist. If EXP_FULL is true,
* perform splitting and file name expansion. When arglist is NULL, perform
* here document expansion.
*/
void
expandarg(union node *arg, struct arglist *arglist, int flag)
{
struct strlist *sp;
char *p;
argbackq = arg->narg.backquote;
STARTSTACKSTR(expdest);
ifsfirst.next = NULL;
ifslastp = NULL;
argstr(arg->narg.text, flag);
if (arglist == NULL) {
return; /* here document expanded */
}
STPUTC('\0', expdest);
p = grabstackstr(expdest);
exparg.lastp = &exparg.list;
/*
* TODO - EXP_REDIR
*/
if (flag & EXP_FULL) {
ifsbreakup(p, &exparg);
*exparg.lastp = NULL;
exparg.lastp = &exparg.list;
expandmeta(exparg.list, flag);
} else {
if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
rmescapes(p);
sp = (struct strlist *)stalloc(sizeof (struct strlist));
sp->text = p;
*exparg.lastp = sp;
exparg.lastp = &sp->next;
}
while (ifsfirst.next != NULL) {
struct ifsregion *ifsp;
INTOFF;
ifsp = ifsfirst.next->next;
ckfree(ifsfirst.next);
ifsfirst.next = ifsp;
INTON;
}
*exparg.lastp = NULL;
if (exparg.list) {
*arglist->lastp = exparg.list;
arglist->lastp = exparg.lastp;
}
}
/*
* Perform variable and command substitution. If EXP_FULL is set, output CTLESC
* characters to allow for further processing. Otherwise treat
* $@ like $* since no splitting will be performed.
*/
STATIC void
argstr(char *p, int flag)
{
char c;
int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); /* do CTLESC */
int firsteq = 1;
if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
p = exptilde(p, flag);
for (;;) {
switch (c = *p++) {
case '\0':
case CTLENDVAR: /* ??? */
goto breakloop;
case CTLQUOTEMARK:
/* "$@" syntax adherence hack */
if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
break;
if ((flag & EXP_FULL) != 0)
STPUTC(c, expdest);
break;
case CTLESC:
if (quotes)
STPUTC(c, expdest);
c = *p++;
STPUTC(c, expdest);
break;
case CTLVAR:
p = evalvar(p, flag);
break;
case CTLBACKQ:
case CTLBACKQ|CTLQUOTE:
expbackq(argbackq->n, c & CTLQUOTE, flag);
argbackq = argbackq->next;
break;
case CTLENDARI:
expari(flag);
break;
case ':':
case '=':
/*
* sort of a hack - expand tildes in variable
* assignments (after the first '=' and after ':'s).
*/
STPUTC(c, expdest);
if (flag & EXP_VARTILDE && *p == '~') {
if (c == '=') {
if (firsteq)
firsteq = 0;
else
break;
}
p = exptilde(p, flag);
}
break;
default:
STPUTC(c, expdest);
}
}
breakloop:;
}
STATIC char *
exptilde(char *p, int flag)
{
char c, *startp = p;
struct passwd *pw;
char *home;
int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
while ((c = *p) != '\0') {
switch(c) {
case CTLESC:
return (startp);
case CTLQUOTEMARK:
return (startp);
case ':':
if (flag & EXP_VARTILDE)
goto done;
break;
case '/':
goto done;
}
p++;
}
done:
*p = '\0';
if (*(startp+1) == '\0') {
if ((home = lookupvar("HOME")) == NULL)
goto lose;
} else {
if ((pw = getpwnam(startp+1)) == NULL)
goto lose;
home = pw->pw_dir;
}
if (*home == '\0')
goto lose;
*p = c;
while ((c = *home++) != '\0') {
if (quotes && SQSYNTAX[(int)c] == CCTL)
STPUTC(CTLESC, expdest);
STPUTC(c, expdest);
}
return (p);
lose:
*p = c;
return (startp);
}
STATIC void
removerecordregions(int endoff)
{
if (ifslastp == NULL)
return;
if (ifsfirst.endoff > endoff) {
while (ifsfirst.next != NULL) {
struct ifsregion *ifsp;
INTOFF;
ifsp = ifsfirst.next->next;
ckfree(ifsfirst.next);
ifsfirst.next = ifsp;
INTON;
}
if (ifsfirst.begoff > endoff)
ifslastp = NULL;
else {
ifslastp = &ifsfirst;
ifsfirst.endoff = endoff;
}
return;
}
ifslastp = &ifsfirst;
while (ifslastp->next && ifslastp->next->begoff < endoff)
ifslastp=ifslastp->next;
while (ifslastp->next != NULL) {
struct ifsregion *ifsp;
INTOFF;
ifsp = ifslastp->next->next;
ckfree(ifslastp->next);
ifslastp->next = ifsp;
INTON;
}
if (ifslastp->endoff > endoff)
ifslastp->endoff = endoff;
}
/*
* Expand arithmetic expression. Backup to start of expression,
* evaluate, place result in (backed up) result, adjust string position.
*/
void
expari(int flag)
{
char *p, *start;
int result;
int begoff;
int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
int quoted;
/*
* This routine is slightly over-complicated for
* efficiency. First we make sure there is
* enough space for the result, which may be bigger
* than the expression if we add exponentiation. Next we
* scan backwards looking for the start of arithmetic. If the
* next previous character is a CTLESC character, then we
* have to rescan starting from the beginning since CTLESC
* characters have to be processed left to right.
*/
#if INT_MAX / 1000000000 >= 10 || INT_MIN / 1000000000 <= -10
#error "integers with more than 10 digits are not supported"
#endif
CHECKSTRSPACE(12 - 2, expdest);
USTPUTC('\0', expdest);
start = stackblock();
p = expdest - 2;
while (p >= start && *p != CTLARI)
--p;
if (p < start || *p != CTLARI)
error("missing CTLARI (shouldn't happen)");
if (p > start && *(p - 1) == CTLESC)
for (p = start; *p != CTLARI; p++)
if (*p == CTLESC)
p++;
if (p[1] == '"')
quoted=1;
else
quoted=0;
begoff = p - start;
removerecordregions(begoff);
if (quotes)
rmescapes(p+2);
result = arith(p+2);
fmtstr(p, 12, "%d", result);
while (*p++)
;
if (quoted == 0)
recordregion(begoff, p - 1 - start, 0);
result = expdest - p + 1;
STADJUST(-result, expdest);
}
/*
* Expand stuff in backwards quotes.
*/
STATIC void
expbackq(union node *cmd, int quoted, int flag)
{
struct backcmd in;
int i;
char buf[128];
char *p;
char *dest = expdest;
struct ifsregion saveifs, *savelastp;
struct nodelist *saveargbackq;
char lastc;
int startloc = dest - stackblock();
char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
int saveherefd;
int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
int nnl;
INTOFF;
saveifs = ifsfirst;
savelastp = ifslastp;
saveargbackq = argbackq;
saveherefd = herefd;
herefd = -1;
p = grabstackstr(dest);
evalbackcmd(cmd, &in);
ungrabstackstr(p, dest);
ifsfirst = saveifs;
ifslastp = savelastp;
argbackq = saveargbackq;
herefd = saveherefd;
p = in.buf;
lastc = '\0';
nnl = 0;
/* Don't copy trailing newlines */
for (;;) {
if (--in.nleft < 0) {
if (in.fd < 0)
break;
while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
TRACE(("expbackq: read returns %d\n", i));
if (i <= 0)
break;
p = buf;
in.nleft = i - 1;
}
lastc = *p++;
if (lastc != '\0') {
if (quotes && syntax[(int)lastc] == CCTL)
STPUTC(CTLESC, dest);
if (lastc == '\n') {
nnl++;
} else {
while (nnl > 0) {
nnl--;
STPUTC('\n', dest);
}
STPUTC(lastc, dest);
}
}
}
if (in.fd >= 0)
close(in.fd);
if (in.buf)
ckfree(in.buf);
if (in.jp)
exitstatus = waitforjob(in.jp, (int *)NULL);
if (quoted == 0)
recordregion(startloc, dest - stackblock(), 0);
TRACE(("evalbackq: size=%d: \"%.*s\"\n",
(dest - stackblock()) - startloc,
(dest - stackblock()) - startloc,
stackblock() + startloc));
expdest = dest;
INTON;
}
STATIC int
subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
int varflags)
{
char *startp;
char *loc = NULL;
char *q;
int c = 0;
int saveherefd = herefd;
struct nodelist *saveargbackq = argbackq;
int amount;
herefd = -1;
argstr(p, 0);
STACKSTRNUL(expdest);
herefd = saveherefd;
argbackq = saveargbackq;
startp = stackblock() + startloc;
if (str == NULL)
str = stackblock() + strloc;
switch (subtype) {
case VSASSIGN:
setvar(str, startp, 0);
amount = startp - expdest;
STADJUST(amount, expdest);
varflags &= ~VSNUL;
if (c != 0)
*loc = c;
return 1;
case VSQUESTION:
if (*p != CTLENDVAR) {
outfmt(&errout, "%s\n", startp);
error((char *)NULL);
}
error("%.*s: parameter %snot set", (int)(p - str - 1),
str, (varflags & VSNUL) ? "null or "
: nullstr);
return 0;
case VSTRIMLEFT:
for (loc = startp; loc < str; loc++) {
c = *loc;
*loc = '\0';
if (patmatch(str, startp, varflags & VSQUOTE)) {
*loc = c;
goto recordleft;
}
*loc = c;
if ((varflags & VSQUOTE) && *loc == CTLESC)
loc++;
}
return 0;
case VSTRIMLEFTMAX:
for (loc = str - 1; loc >= startp;) {
c = *loc;
*loc = '\0';
if (patmatch(str, startp, varflags & VSQUOTE)) {
*loc = c;
goto recordleft;
}
*loc = c;
loc--;
if ((varflags & VSQUOTE) && loc > startp &&
*(loc - 1) == CTLESC) {
for (q = startp; q < loc; q++)
if (*q == CTLESC)
q++;
if (q > loc)
loc--;
}
}
return 0;
case VSTRIMRIGHT:
for (loc = str - 1; loc >= startp;) {
if (patmatch(str, loc, varflags & VSQUOTE)) {
amount = loc - expdest;
STADJUST(amount, expdest);
return 1;
}
loc--;
if ((varflags & VSQUOTE) && loc > startp &&
*(loc - 1) == CTLESC) {
for (q = startp; q < loc; q++)
if (*q == CTLESC)
q++;
if (q > loc)
loc--;
}
}
return 0;
case VSTRIMRIGHTMAX:
for (loc = startp; loc < str - 1; loc++) {
if (patmatch(str, loc, varflags & VSQUOTE)) {
amount = loc - expdest;
STADJUST(amount, expdest);
return 1;
}
if ((varflags & VSQUOTE) && *loc == CTLESC)
loc++;
}
return 0;
default:
abort();
}
recordleft:
amount = ((str - 1) - (loc - startp)) - expdest;
STADJUST(amount, expdest);
while (loc != str - 1)
*startp++ = *loc++;
return 1;
}
/*
* Expand a variable, and return a pointer to the next character in the
* input string.
*/
STATIC char *
evalvar(char *p, int flag)
{
int subtype;
int varflags;
char *var;
char *val;
int patloc;
int c;
int set;
int special;
int startloc;
int varlen;
int easy;
int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
varflags = *p++;
subtype = varflags & VSTYPE;
var = p;
special = 0;
if (! is_name(*p))
special = 1;
p = strchr(p, '=') + 1;
again: /* jump here after setting a variable with ${var=text} */
if (special) {
set = varisset(var, varflags & VSNUL);
val = NULL;
} else {
val = bltinlookup(var, 1);
if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
val = NULL;
set = 0;
} else
set = 1;
}
varlen = 0;
startloc = expdest - stackblock();
if (!set && uflag) {
switch (subtype) {
case VSNORMAL:
case VSTRIMLEFT:
case VSTRIMLEFTMAX:
case VSTRIMRIGHT:
case VSTRIMRIGHTMAX:
case VSLENGTH:
error("%.*s: parameter not set", (int)(p - var - 1),
var);
}
}
if (set && subtype != VSPLUS) {
/* insert the value of the variable */
if (special) {
varvalue(var, varflags & VSQUOTE, flag & EXP_FULL);
if (subtype == VSLENGTH) {
varlen = expdest - stackblock() - startloc;
STADJUST(-varlen, expdest);
}
} else {
char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
: BASESYNTAX;
if (subtype == VSLENGTH) {
for (;*val; val++)
varlen++;
}
else {
while (*val) {
if (quotes &&
syntax[(int)*val] == CCTL)
STPUTC(CTLESC, expdest);
STPUTC(*val++, expdest);
}
}
}
}
if (subtype == VSPLUS)
set = ! set;
easy = ((varflags & VSQUOTE) == 0 ||
(*var == '@' && shellparam.nparam != 1));
switch (subtype) {
case VSLENGTH:
expdest = cvtnum(varlen, expdest);
goto record;
case VSNORMAL:
if (!easy)
break;
record:
recordregion(startloc, expdest - stackblock(),
varflags & VSQUOTE);
break;
case VSPLUS:
case VSMINUS:
if (!set) {
argstr(p, flag);
break;
}
if (easy)
goto record;
break;
case VSTRIMLEFT:
case VSTRIMLEFTMAX:
case VSTRIMRIGHT:
case VSTRIMRIGHTMAX:
if (!set)
break;
/*
* Terminate the string and start recording the pattern
* right after it
*/
STPUTC('\0', expdest);
patloc = expdest - stackblock();
if (subevalvar(p, NULL, patloc, subtype,
startloc, varflags) == 0) {
int amount = (expdest - stackblock() - patloc) + 1;
STADJUST(-amount, expdest);
}
/* Remove any recorded regions beyond start of variable */
removerecordregions(startloc);
goto record;
case VSASSIGN:
case VSQUESTION:
if (!set) {
if (subevalvar(p, var, 0, subtype, startloc, varflags)) {
varflags &= ~VSNUL;
/*
* Remove any recorded regions beyond
* start of variable
*/
removerecordregions(startloc);
goto again;
}
break;
}
if (easy)
goto record;
break;
default:
abort();
}
if (subtype != VSNORMAL) { /* skip to end of alternative */
int nesting = 1;
for (;;) {
if ((c = *p++) == CTLESC)
p++;
else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
if (set)
argbackq = argbackq->next;
} else if (c == CTLVAR) {
if ((*p++ & VSTYPE) != VSNORMAL)
nesting++;
} else if (c == CTLENDVAR) {
if (--nesting == 0)
break;
}
}
}
return p;
}
/*
* Test whether a specialized variable is set.
*/
STATIC int
varisset(char *name, int nulok)
{
if (*name == '!')
return backgndpid != -1;
else if (*name == '@' || *name == '*') {
if (*shellparam.p == NULL)
return 0;
if (nulok) {
char **av;
for (av = shellparam.p; *av; av++)
if (**av != '\0')
return 1;
return 0;
}
} else if (is_digit(*name)) {
char *ap;
int num = atoi(name);
if (num > shellparam.nparam)
return 0;
if (num == 0)
ap = arg0;
else
ap = shellparam.p[num - 1];
if (nulok && (ap == NULL || *ap == '\0'))
return 0;
}
return 1;
}
/*
* Add the value of a specialized variable to the stack string.
*/
STATIC void
varvalue(char *name, int quoted, int allow_split)
{
int num;
char *p;
int i;
extern int oexitstatus;
char sep;
char **ap;
char const *syntax;
#define STRTODEST(p) \
do {\
if (allow_split) { \
syntax = quoted? DQSYNTAX : BASESYNTAX; \
while (*p) { \
if (syntax[(int)*p] == CCTL) \
STPUTC(CTLESC, expdest); \
STPUTC(*p++, expdest); \
} \
} else \
while (*p) \
STPUTC(*p++, expdest); \
} while (0)
switch (*name) {
case '$':
num = rootpid;
goto numvar;
case '?':
num = oexitstatus;
goto numvar;
case '#':
num = shellparam.nparam;
goto numvar;
case '!':
num = backgndpid;
numvar:
expdest = cvtnum(num, expdest);
break;
case '-':
for (i = 0 ; i < NOPTS ; i++) {
if (optlist[i].val)
STPUTC(optlist[i].letter, expdest);
}
break;
case '@':
if (allow_split && quoted) {
for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
STRTODEST(p);
if (*ap)
STPUTC('\0', expdest);
}
break;
}
/* FALLTHROUGH */
case '*':
if (ifsset())
sep = ifsval()[0];
else
sep = ' ';
for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
STRTODEST(p);
if (*ap && sep)
STPUTC(sep, expdest);
}
break;
case '0':
p = arg0;
STRTODEST(p);
break;
default:
if (is_digit(*name)) {
num = atoi(name);
if (num > 0 && num <= shellparam.nparam) {
p = shellparam.p[num - 1];
STRTODEST(p);
}
}
break;
}
}
/*
* Record the the fact that we have to scan this region of the
* string for IFS characters.
*/
STATIC void
recordregion(int start, int end, int nulonly)
{
struct ifsregion *ifsp;
if (ifslastp == NULL) {
ifsp = &ifsfirst;
} else {
ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
ifslastp->next = ifsp;
}
ifslastp = ifsp;
ifslastp->next = NULL;
ifslastp->begoff = start;
ifslastp->endoff = end;
ifslastp->nulonly = nulonly;
}
/*
* Break the argument string into pieces based upon IFS and add the
* strings to the argument list. The regions of the string to be
* searched for IFS characters have been stored by recordregion.
*/
STATIC void
ifsbreakup(char *string, struct arglist *arglist)
{
struct ifsregion *ifsp;
struct strlist *sp;
char *start;
char *p;
char *q;
char *ifs;
int ifsspc;
int nulonly;
start = string;
ifsspc = 0;
nulonly = 0;
if (ifslastp != NULL) {
ifsp = &ifsfirst;
do {
p = string + ifsp->begoff;
nulonly = ifsp->nulonly;
ifs = nulonly ? nullstr :
( ifsset() ? ifsval() : " \t\n" );
ifsspc = 0;
while (p < string + ifsp->endoff) {
q = p;
if (*p == CTLESC)
p++;
if (strchr(ifs, *p)) {
if (!nulonly)
ifsspc = (strchr(" \t\n", *p) != NULL);
/* Ignore IFS whitespace at start */
if (q == start && ifsspc) {
p++;
start = p;
continue;
}
*q = '\0';
sp = (struct strlist *)stalloc(sizeof *sp);
sp->text = start;
*arglist->lastp = sp;
arglist->lastp = &sp->next;
p++;
if (!nulonly) {
for (;;) {
if (p >= string + ifsp->endoff) {
break;
}
q = p;
if (*p == CTLESC)
p++;
if (strchr(ifs, *p) == NULL ) {
p = q;
break;
} else if (strchr(" \t\n",*p) == NULL) {
if (ifsspc) {
p++;
ifsspc = 0;
} else {
p = q;
break;
}
} else
p++;
}
}
start = p;
} else
p++;
}
} while ((ifsp = ifsp->next) != NULL);
if (*start || (!ifsspc && start > string)) {
sp = (struct strlist *)stalloc(sizeof *sp);
sp->text = start;
*arglist->lastp = sp;
arglist->lastp = &sp->next;
}
} else {
sp = (struct strlist *)stalloc(sizeof *sp);
sp->text = start;
*arglist->lastp = sp;
arglist->lastp = &sp->next;
}
}
/*
* Expand shell metacharacters. At this point, the only control characters
* should be escapes. The results are stored in the list exparg.
*/
STATIC char *expdir;
STATIC void
expandmeta(struct strlist *str, int flag __unused)
{
char *p;
struct strlist **savelastp;
struct strlist *sp;
char c;
/* TODO - EXP_REDIR */
while (str) {
if (fflag)
goto nometa;
p = str->text;
for (;;) { /* fast check for meta chars */
if ((c = *p++) == '\0')
goto nometa;
if (c == '*' || c == '?' || c == '[' || c == '!')
break;
}
savelastp = exparg.lastp;
INTOFF;
if (expdir == NULL) {
int i = strlen(str->text);
expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */
}
expmeta(expdir, str->text);
ckfree(expdir);
expdir = NULL;
INTON;
if (exparg.lastp == savelastp) {
/*
* no matches
*/
nometa:
*exparg.lastp = str;
rmescapes(str->text);
exparg.lastp = &str->next;
} else {
*exparg.lastp = NULL;
*savelastp = sp = expsort(*savelastp);
while (sp->next != NULL)
sp = sp->next;
exparg.lastp = &sp->next;
}
str = str->next;
}
}
/*
* Do metacharacter (i.e. *, ?, [...]) expansion.
*/
STATIC void
expmeta(char *enddir, char *name)
{
char *p;
char *q;
char *start;
char *endname;
int metaflag;
struct stat statb;
DIR *dirp;
struct dirent *dp;
int atend;
int matchdot;
metaflag = 0;
start = name;
for (p = name ; ; p++) {
if (*p == '*' || *p == '?')
metaflag = 1;
else if (*p == '[') {
q = p + 1;
if (*q == '!' || *q == '^')
q++;
for (;;) {
while (*q == CTLQUOTEMARK)
q++;
if (*q == CTLESC)
q++;
if (*q == '/' || *q == '\0')
break;
if (*++q == ']') {
metaflag = 1;
break;
}
}
} else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) {
metaflag = 1;
} else if (*p == '\0')
break;
else if (*p == CTLQUOTEMARK)
continue;
else if (*p == CTLESC)
p++;
if (*p == '/') {
if (metaflag)
break;
start = p + 1;
}
}
if (metaflag == 0) { /* we've reached the end of the file name */
if (enddir != expdir)
metaflag++;
for (p = name ; ; p++) {
if (*p == CTLQUOTEMARK)
continue;
if (*p == CTLESC)
p++;
*enddir++ = *p;
if (*p == '\0')
break;
}
if (metaflag == 0 || lstat(expdir, &statb) >= 0)
addfname(expdir);
return;
}
endname = p;
if (start != name) {
p = name;
while (p < start) {
while (*p == CTLQUOTEMARK)
p++;
if (*p == CTLESC)
p++;
*enddir++ = *p++;
}
}
if (enddir == expdir) {
p = ".";
} else if (enddir == expdir + 1 && *expdir == '/') {
p = "/";
} else {
p = expdir;
enddir[-1] = '\0';
}
if ((dirp = opendir(p)) == NULL)
return;
if (enddir != expdir)
enddir[-1] = '/';
if (*endname == 0) {
atend = 1;
} else {
atend = 0;
*endname++ = '\0';
}
matchdot = 0;
p = start;
while (*p == CTLQUOTEMARK)
p++;
if (*p == CTLESC)
p++;
if (*p == '.')
matchdot++;
while (! int_pending() && (dp = readdir(dirp)) != NULL) {
if (dp->d_name[0] == '.' && ! matchdot)
continue;
if (patmatch(start, dp->d_name, 0)) {
if (atend) {
scopy(dp->d_name, enddir);
addfname(expdir);
} else {
for (p = enddir, q = dp->d_name;
(*p++ = *q++) != '\0';)
continue;
p[-1] = '/';
expmeta(p, endname);
}
}
}
closedir(dirp);
if (! atend)
endname[-1] = '/';
}
/*
* Add a file name to the list.
*/
STATIC void
addfname(char *name)
{
char *p;
struct strlist *sp;
p = stalloc(strlen(name) + 1);
scopy(name, p);
sp = (struct strlist *)stalloc(sizeof *sp);
sp->text = p;
*exparg.lastp = sp;
exparg.lastp = &sp->next;
}
/*
* Sort the results of file name expansion. It calculates the number of
* strings to sort and then calls msort (short for merge sort) to do the
* work.
*/
STATIC struct strlist *
expsort(struct strlist *str)
{
int len;
struct strlist *sp;
len = 0;
for (sp = str ; sp ; sp = sp->next)
len++;
return msort(str, len);
}
STATIC struct strlist *
msort(struct strlist *list, int len)
{
struct strlist *p, *q = NULL;
struct strlist **lpp;
int half;
int n;
if (len <= 1)
return list;
half = len >> 1;
p = list;
for (n = half ; --n >= 0 ; ) {
q = p;
p = p->next;
}
q->next = NULL; /* terminate first half of list */
q = msort(list, half); /* sort first half of list */
p = msort(p, len - half); /* sort second half */
lpp = &list;
for (;;) {
if (strcmp(p->text, q->text) < 0) {
*lpp = p;
lpp = &p->next;
if ((p = *lpp) == NULL) {
*lpp = q;
break;
}
} else {
*lpp = q;
lpp = &q->next;
if ((q = *lpp) == NULL) {
*lpp = p;
break;
}
}
}
return list;
}
/*
* Returns true if the pattern matches the string.
*/
int
patmatch(char *pattern, char *string, int squoted)
{
#ifdef notdef
if (pattern[0] == '!' && pattern[1] == '!')
return 1 - pmatch(pattern + 2, string);
else
#endif
return pmatch(pattern, string, squoted);
}
STATIC int
pmatch(char *pattern, char *string, int squoted)
{
char *p, *q;
char c;
p = pattern;
q = string;
for (;;) {
switch (c = *p++) {
case '\0':
goto breakloop;
case CTLESC:
if (squoted && *q == CTLESC)
q++;
if (*q++ != *p++)
return 0;
break;
case CTLQUOTEMARK:
continue;
case '?':
if (squoted && *q == CTLESC)
q++;
if (*q++ == '\0')
return 0;
break;
case '*':
c = *p;
while (c == CTLQUOTEMARK || c == '*')
c = *++p;
if (c != CTLESC && c != CTLQUOTEMARK &&
c != '?' && c != '*' && c != '[') {
while (*q != c) {
if (squoted && *q == CTLESC &&
q[1] == c)
break;
if (*q == '\0')
return 0;
if (squoted && *q == CTLESC)
q++;
q++;
}
}
do {
if (pmatch(p, q, squoted))
return 1;
if (squoted && *q == CTLESC)
q++;
} while (*q++ != '\0');
return 0;
case '[': {
char *endp;
int invert, found;
char chr;
endp = p;
if (*endp == '!' || *endp == '^')
endp++;
for (;;) {
while (*endp == CTLQUOTEMARK)
endp++;
if (*endp == '\0')
goto dft; /* no matching ] */
if (*endp == CTLESC)
endp++;
if (*++endp == ']')
break;
}
invert = 0;
if (*p == '!' || *p == '^') {
invert++;
p++;
}
found = 0;
chr = *q++;
if (squoted && chr == CTLESC)
chr = *q++;
if (chr == '\0')
return 0;
c = *p++;
do {
if (c == CTLQUOTEMARK)
continue;
if (c == CTLESC)
c = *p++;
if (*p == '-' && p[1] != ']') {
p++;
while (*p == CTLQUOTEMARK)
p++;
if (*p == CTLESC)
p++;
if ( collate_range_cmp(chr, c) >= 0
&& collate_range_cmp(chr, *p) <= 0
)
found = 1;
p++;
} else {
if (chr == c)
found = 1;
}
} while ((c = *p++) != ']');
if (found == invert)
return 0;
break;
}
dft: default:
if (squoted && *q == CTLESC)
q++;
if (*q++ != c)
return 0;
break;
}
}
breakloop:
if (*q != '\0')
return 0;
return 1;
}
/*
* Remove any CTLESC characters from a string.
*/
void
rmescapes(char *str)
{
char *p, *q;
p = str;
while (*p != CTLESC && *p != CTLQUOTEMARK) {
if (*p++ == '\0')
return;
}
q = p;
while (*p) {
if (*p == CTLQUOTEMARK) {
p++;
continue;
}
if (*p == CTLESC)
p++;
*q++ = *p++;
}
*q = '\0';
}
/*
* See if a pattern matches in a case statement.
*/
int
casematch(union node *pattern, char *val)
{
struct stackmark smark;
int result;
char *p;
setstackmark(&smark);
argbackq = pattern->narg.backquote;
STARTSTACKSTR(expdest);
ifslastp = NULL;
argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
STPUTC('\0', expdest);
p = grabstackstr(expdest);
result = patmatch(p, val, 0);
popstackmark(&smark);
return result;
}
/*
* Our own itoa().
*/
STATIC char *
cvtnum(int num, char *buf)
{
char temp[32];
int neg = num < 0;
char *p = temp + 31;
temp[31] = '\0';
do {
*--p = num % 10 + '0';
} while ((num /= 10) != 0);
if (neg)
*--p = '-';
while (*p)
STPUTC(*p++, buf);
return buf;
}
/*
* Do most of the work for wordexp(3).
*/
int
wordexpcmd(int argc, char **argv)
{
size_t len;
int i;
out1fmt("%08x", argc - 1);
for (i = 1, len = 0; i < argc; i++)
len += strlen(argv[i]);
out1fmt("%08x", (int)len);
for (i = 1; i < argc; i++) {
out1str(argv[i]);
out1c('\0');
}
return (0);
}
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