NetBSD/bin/sh/expand.c

1832 lines
39 KiB
C

/* $NetBSD: expand.c,v 1.112 2017/06/05 02:15:55 kre Exp $ */
/*-
* 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.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95";
#else
__RCSID("$NetBSD: expand.c,v 1.112 2017/06/05 02:15:55 kre Exp $");
#endif
#endif /* not lint */
#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 <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include <wctype.h>
#include <wchar.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 "arithmetic.h"
#include "parser.h"
#include "jobs.h"
#include "options.h"
#include "builtins.h"
#include "var.h"
#include "input.h"
#include "output.h"
#include "memalloc.h"
#include "error.h"
#include "mystring.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 inquotes; /* search for nul bytes only */
};
char *expdest; /* output of current string */
struct nodelist *argbackq; /* list of back quote expressions */
struct ifsregion ifsfirst; /* first struct in list of ifs regions */
struct ifsregion *ifslastp; /* last struct in list */
struct arglist exparg; /* holds expanded arg list */
STATIC const char *argstr(const char *, int);
STATIC const char *exptilde(const char *, int);
STATIC void expbackq(union node *, int, int);
STATIC const char *expari(const char *, int);
STATIC int subevalvar(const char *, const char *, int, int, int);
STATIC int subevalvar_trim(const char *, int, int, int, int, int);
STATIC const char *evalvar(const char *, int);
STATIC int varisset(const char *, int);
STATIC void varvalue(const char *, int, int, int);
STATIC void recordregion(int, int, int);
STATIC void removerecordregions(int);
STATIC void ifsbreakup(char *, struct arglist *);
STATIC void ifsfree(void);
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 patmatch(const char *, const char *, int);
STATIC char *cvtnum(int, char *);
static int collate_range_cmp(wchar_t, wchar_t);
STATIC void add_args(struct strlist *);
/*
* Expand shell variables and backquotes inside a here document.
*/
void
expandhere(union node *arg, int fd)
{
herefd = fd;
expandarg(arg, NULL, 0);
xwrite(fd, stackblock(), expdest - stackblock());
}
static int
collate_range_cmp(wchar_t c1, wchar_t c2)
{
wchar_t s1[2], s2[2];
s1[0] = c1;
s1[1] = L'\0';
s2[0] = c2;
s2[1] = L'\0';
return (wcscoll(s1, s2));
}
/*
* 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;
CTRACE(DBG_EXPAND, ("expandarg(fl=%#x)\n", flag));
if (fflag) /* no filename expandsion */
flag &= ~EXP_GLOB;
argbackq = arg->narg.backquote;
STARTSTACKSTR(expdest);
ifsfirst.next = NULL;
ifslastp = NULL;
argstr(arg->narg.text, flag);
if (arglist == NULL) {
STACKSTRNUL(expdest);
CTRACE(DBG_EXPAND, ("expandarg: no arglist, done (%d) \"%s\"\n",
expdest - stackblock(), stackblock()));
return; /* here document expanded */
}
STPUTC('\0', expdest);
CTRACE(DBG_EXPAND, ("expandarg: arglist got (%d) \"%s\"\n",
expdest - stackblock() - 1, stackblock()));
p = grabstackstr(expdest);
exparg.lastp = &exparg.list;
/*
* TODO - EXP_REDIR
*/
if (flag & EXP_SPLIT) {
ifsbreakup(p, &exparg);
*exparg.lastp = NULL;
exparg.lastp = &exparg.list;
if (flag & EXP_GLOB)
expandmeta(exparg.list, flag);
else
add_args(exparg.list);
} else {
if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
rmescapes(p);
sp = stalloc(sizeof(*sp));
sp->text = p;
*exparg.lastp = sp;
exparg.lastp = &sp->next;
}
ifsfree();
*exparg.lastp = NULL;
if (exparg.list) {
*arglist->lastp = exparg.list;
arglist->lastp = exparg.lastp;
}
}
/*
* Perform variable and command substitution.
* If EXP_GLOB is set, output CTLESC characters to allow for further processing.
* If EXP_SPLIT is set, remember location of result for later,
* Otherwise treat $@ like $* since no splitting will be performed.
*/
STATIC const char *
argstr(const char *p, int flag)
{
char c;
int quotes = flag & (EXP_GLOB | EXP_CASE | EXP_REDIR); /* do CTLESC */
int firsteq = 1;
const char *ifs = NULL;
int ifs_split = EXP_IFS_SPLIT;
#ifdef DEBUG
const char *ed = expdest;
#endif
if (flag & EXP_IFS_SPLIT)
ifs = ifsval();
CTRACE(DBG_EXPAND, ("argstr(\"%s\", %#x) quotes=%#x\n", p,flag,quotes));
if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
p = exptilde(p, flag);
for (;;) {
switch (c = *p++) {
case '\0':
VTRACE(DBG_EXPAND, ("argstr returning at \"\" "
"added \"%.*s\" to expdest (followed by: %2.2x)\n",
expdest-ed, ed, *expdest));
return p - 1;
case CTLENDVAR: /* end of expanding yyy in ${xxx-yyy} */
case CTLENDARI: /* end of a $(( )) string */
VTRACE(DBG_EXPAND, ("argstr returning at \"%.6s\"..."
" after %2.2x; "
"added \"%.*s\" to expdest (followed by: %2.2x)\n",
p, p[-1]&0xff, expdest-ed, ed, *expdest));
return p;
case CTLQUOTEMARK:
/* "$@" syntax adherence hack */
if (p[0] == CTLVAR && p[1] & VSQUOTE &&
p[2] == '@' && p[3] == '=')
break;
if ((flag & EXP_SPLIT) != 0)
STPUTC(c, expdest);
ifs_split = 0;
break;
case CTLQUOTEEND:
ifs_split = EXP_IFS_SPLIT;
break;
case CTLESC:
if (quotes)
STPUTC(c, expdest);
c = *p++;
STPUTC(c, expdest);
break;
case CTLVAR:
p = evalvar(p, (flag & ~EXP_IFS_SPLIT) | (flag & ifs_split));
VTRACE(DBG_EXPAND, ("argstr evalvar "
"added \"%.*s\" to expdest (followed by: %2.2x)\n",
expdest-ed, ed, *expdest));
break;
case CTLBACKQ:
case CTLBACKQ|CTLQUOTE:
expbackq(argbackq->n, c & CTLQUOTE, flag);
argbackq = argbackq->next;
VTRACE(DBG_EXPAND, ("argstr expbackq "
"added \"%.*s\" to expdest (followed by: %2.2x)\n",
expdest-ed, ed, *expdest));
break;
case CTLARI:
p = expari(p, flag);
VTRACE(DBG_EXPAND, ("argstr expari "
"+ \"%.*s\" to dest (fwd by: %2.2x) p=\"%.5s...\"\n",
expdest-ed, ed, *expdest, p));
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);
if (flag & ifs_split && strchr(ifs, c) != NULL) {
/* We need to get the output split here... */
recordregion(expdest - stackblock() - 1,
expdest - stackblock(), 0);
}
break;
}
}
}
STATIC const char *
exptilde(const char *p, int flag)
{
char c;
const char *startp = p;
struct passwd *pw;
const char *home;
int quotes = flag & (EXP_GLOB | EXP_CASE);
char *user;
user = expdest; /* we will just borrow top of stack */
while ((c = *++p) != '\0') {
switch(c) {
case CTLESC:
case CTLVAR:
case CTLBACKQ:
case CTLBACKQ | CTLQUOTE:
case CTLARI:
case CTLENDARI:
case CTLQUOTEMARK:
return (startp);
case ':':
if (flag & EXP_VARTILDE)
goto done;
break;
case '/':
goto done;
}
STPUTC(c, user);
}
done:
STACKSTRNUL(user);
CTRACE(DBG_EXPAND, ("exptilde, found \"%s\" :", expdest));
if (*expdest == '\0')
home = lookupvar("HOME");
else if ((pw = getpwnam(expdest)) == NULL)
home = NULL;
else
home = pw->pw_dir;
STUNSTR(user - expdest); /* return borrowed string space */
if (home == NULL || *home == '\0')
return startp;
while ((c = *home++) != '\0') {
if (quotes && SQSYNTAX[(int)c] == CCTL)
STPUTC(CTLESC, expdest);
STPUTC(c, expdest);
}
CTRACE(DBG_EXPAND, ("returning \"%s\"\n", p));
return (p);
}
STATIC void
removerecordregions(int endoff)
{
VTRACE(DBG_EXPAND, ("removerecordregions(%d):", endoff));
if (ifslastp == NULL) {
VTRACE(DBG_EXPAND, (" none\n", endoff));
return;
}
if (ifsfirst.endoff > endoff) {
VTRACE(DBG_EXPAND, (" first(%d)", ifsfirst.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 {
VTRACE(DBG_EXPAND,("->(%d,%d)",ifsfirst.begoff,endoff));
ifslastp = &ifsfirst;
ifsfirst.endoff = endoff;
}
VTRACE(DBG_EXPAND, ("\n"));
return;
}
ifslastp = &ifsfirst;
while (ifslastp->next && ifslastp->next->begoff < endoff)
ifslastp=ifslastp->next;
VTRACE(DBG_EXPAND, (" found(%d,%d)", ifslastp->begoff,ifslastp->endoff));
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;
VTRACE(DBG_EXPAND, ("->(%d,%d)", ifslastp->begoff,ifslastp->endoff));
}
/*
* Expand arithmetic expression. Backup to start of expression,
* evaluate, place result in (backed up) result, adjust string position.
*/
STATIC const char *
expari(const char *p, int flag)
{
char *q, *start;
intmax_t result;
int adjustment;
int begoff;
int quotes = flag & (EXP_GLOB | EXP_CASE);
int quoted;
#ifdef DEBUG
const char *ed = expdest;
#endif
/* ifsfree(); */
/*
* 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 exponentation. 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.
*/
/*
* SPACE_NEEDED is enough for all possible digits (rounded up)
* plus possible "-", and the terminating '\0', hence, plus 2
*
* The calculation produces the number of bytes needed to
* represent the biggest possible value, in octal. We only
* generate decimal, which takes (often) less digits (never more)
* so this is safe, if occasionally slightly wasteful.
*/
#define SPACE_NEEDED ((int)((sizeof(intmax_t) * CHAR_BIT + 2) / 3 + 2))
/*
* Only need check for SPACE_NEEDED-2 as we have already
* consumed (but will overwrite) 2 chars, the CTLARI, and the
* flags (quoting) byte (if those had not already been seen,
* we would not be here.)
*/
quoted = *p++ == '"';
begoff = expdest - stackblock();
VTRACE(DBG_EXPAND, ("expari: '%c' \"%s\" begoff %d\n", p[-1],p,begoff));
p = argstr(p, 0); /* expand $(( )) string */
STPUTC('\0', expdest);
start = stackblock() + begoff;
VTRACE(DBG_EXPAND, ("expari: argstr added: '%s' start: \"%.8s\"\n",
ed, start));
removerecordregions(begoff);
if (quotes)
rmescapes(start); /* should be a no-op */
q = grabstackstr(expdest);
result = arith(start);
VTRACE(DBG_EXPAND, ("expari: after arith: result=%jd '%s' q@'%.3s'\n",
result, ed, q));
ungrabstackstr(q, expdest);
start = stackblock() + begoff;
adjustment = expdest - start;
VTRACE(DBG_EXPAND, ("expari: removing %d ", adjustment));
STADJUST(-adjustment, expdest); /* remove the argstr() */
VTRACE(DBG_EXPAND, ("ed \"%.*s\", expdest \"%s\"\n",
expdest-ed, ed, expdest));
CHECKSTRSPACE(SPACE_NEEDED, expdest);
fmtstr(expdest, SPACE_NEEDED, "%"PRIdMAX, result);
VTRACE(DBG_EXPAND, ("expari: after fmtstr: ed \"%s\" expdest \"%s\"\n",
ed, expdest));
for (q = expdest; *q++ != '\0'; )
;
if (quoted == 0) /* allow weird splitting */
recordregion(begoff, begoff + q - 1 - expdest, 0);
adjustment = q - expdest - 1;
STADJUST(adjustment, expdest);
VTRACE(DBG_EXPAND, ("expari: adding %d ed \"%.*s\", "
"expdest \"%s\" returning \"%.5s...\"\n", adjustment, expdest - ed,
ed, expdest, p));
return p;
}
/*
* 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_GLOB | EXP_CASE);
int nnl;
VTRACE(DBG_EXPAND, ("expbackq( ..., q=%d flag=%#x)\n", quoted, flag));
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;
for (;;) {
if (--in.nleft < 0) {
if (in.fd < 0)
break;
while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR)
continue;
VTRACE(DBG_EXPAND, ("expbackq: read returns %d\n", i));
if (i <= 0)
break;
p = buf;
in.nleft = i - 1;
}
lastc = *p++;
if (lastc != '\0') {
if (lastc == '\n')
nnl++;
else {
CHECKSTRSPACE(nnl + 2, dest);
while (nnl > 0) {
nnl--;
USTPUTC('\n', dest);
}
if (quotes && syntax[(int)lastc] == CCTL)
USTPUTC(CTLESC, dest);
USTPUTC(lastc, dest);
}
}
}
if (in.fd >= 0)
close(in.fd);
if (in.buf)
ckfree(in.buf);
if (in.jp)
back_exitstatus = waitforjob(in.jp);
if (quoted == 0)
recordregion(startloc, dest - stackblock(), 0);
CTRACE(DBG_EXPAND, ("evalbackq: size=%d: \"%.*s\"\n",
(int)((dest - stackblock()) - startloc),
(int)((dest - stackblock()) - startloc),
stackblock() + startloc));
expdest = dest;
INTON;
}
STATIC int
subevalvar(const char *p, const char *str, int subtype, int startloc,
int varflags)
{
char *startp;
int saveherefd = herefd;
struct nodelist *saveargbackq = argbackq;
int amount;
herefd = -1;
argstr(p, EXP_TILDE);
STACKSTRNUL(expdest);
herefd = saveherefd;
argbackq = saveargbackq;
startp = stackblock() + startloc;
switch (subtype) {
case VSASSIGN:
setvar(str, startp, 0);
amount = startp - expdest;
STADJUST(amount, expdest);
varflags &= ~VSNUL;
return 1;
case VSQUESTION:
if (*p != CTLENDVAR) {
outfmt(&errout, "%s\n", startp);
error(NULL);
}
error("%.*s: parameter %snot set",
(int)(p - str - 1),
str, (varflags & VSNUL) ? "null or "
: nullstr);
/* NOTREACHED */
default:
abort();
}
}
STATIC int
subevalvar_trim(const char *p, int strloc, int subtype, int startloc,
int varflags, int quotes)
{
char *startp;
char *str;
char *loc = NULL;
char *q;
int c = 0;
int saveherefd = herefd;
struct nodelist *saveargbackq = argbackq;
int amount;
herefd = -1;
switch (subtype) {
case VSTRIMLEFT:
case VSTRIMLEFTMAX:
case VSTRIMRIGHT:
case VSTRIMRIGHTMAX:
break;
default:
abort();
break;
}
VTRACE(DBG_EXPAND,
("subevalvar_trim(\"%.9s\", STR@%d, SUBT=%d, start@%d, vf=%x, q=%x)\n",
p, strloc, subtype, startloc, varflags, quotes));
argstr(p, (varflags & (VSQUOTE|VSPATQ)) == VSQUOTE ? 0 : EXP_CASE);
STACKSTRNUL(expdest);
herefd = saveherefd;
argbackq = saveargbackq;
startp = stackblock() + startloc;
str = stackblock() + strloc;
switch (subtype) {
case VSTRIMLEFT:
for (loc = startp; loc < str; loc++) {
c = *loc;
*loc = '\0';
if (patmatch(str, startp, quotes))
goto recordleft;
*loc = c;
if (quotes && *loc == CTLESC)
loc++;
}
return 0;
case VSTRIMLEFTMAX:
for (loc = str - 1; loc >= startp;) {
c = *loc;
*loc = '\0';
if (patmatch(str, startp, quotes))
goto recordleft;
*loc = c;
loc--;
if (quotes && 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, quotes))
goto recordright;
loc--;
if (quotes && 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, quotes))
goto recordright;
if (quotes && *loc == CTLESC)
loc++;
}
return 0;
default:
abort();
}
recordleft:
*loc = c;
amount = ((str - 1) - (loc - startp)) - expdest;
STADJUST(amount, expdest);
while (loc != str - 1)
*startp++ = *loc++;
return 1;
recordright:
amount = loc - expdest;
STADJUST(amount, expdest);
STPUTC('\0', expdest);
STADJUST(-1, expdest);
return 1;
}
/*
* Expand a variable, and return a pointer to the next character in the
* input string.
*/
STATIC const char *
evalvar(const char *p, int flag)
{
int subtype;
int varflags;
const char *var;
char *val;
int patloc;
int c;
int set;
int special;
int startloc;
int varlen;
int apply_ifs;
int quotes = flag & (EXP_GLOB | EXP_CASE | EXP_REDIR);
varflags = (unsigned char)*p++;
subtype = varflags & VSTYPE;
var = p;
special = !is_name(*p);
p = strchr(p, '=') + 1;
CTRACE(DBG_EXPAND,
("evalvar \"%.*s\", flag=%#X quotes=%#X vf=%#X subtype=%X\n",
p - var - 1, var, flag, quotes, varflags, subtype));
again: /* jump here after setting a variable with ${var=text} */
if (varflags & VSLINENO) {
set = 1;
special = p - var;
val = NULL;
} else if (special) {
set = varisset(var, varflags & VSNUL);
val = NULL;
} else {
val = lookupvar(var);
if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
val = NULL;
set = 0;
} else
set = 1;
}
varlen = 0;
startloc = expdest - stackblock();
if (!set && uflag && *var != '@' && *var != '*') {
switch (subtype) {
case VSNORMAL:
case VSTRIMLEFT:
case VSTRIMLEFTMAX:
case VSTRIMRIGHT:
case VSTRIMRIGHTMAX:
case VSLENGTH:
error("%.*s: parameter not set",
(int)(p - var - 1), var);
/* NOTREACHED */
}
}
if (set && subtype != VSPLUS) {
/* insert the value of the variable */
if (special) {
if (varflags & VSLINENO) {
/*
* The LINENO hack
*/
while (--special > 0) {
/* not needed, it is a number...
if (quotes && syntax[(int)*var] == CCTL)
STPUTC(CTLESC, expdest);
*/
STPUTC(*var++, expdest);
}
} else
varvalue(var, varflags&VSQUOTE, subtype, flag);
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 (flag & EXP_IN_QUOTES)
apply_ifs = 0;
else if (varflags & VSQUOTE) {
if (*var == '@' && shellparam.nparam != 1)
apply_ifs = 1;
else {
/*
* Mark so that we don't apply IFS if we recurse through
* here expanding $bar from "${foo-$bar}".
*/
flag |= EXP_IN_QUOTES;
apply_ifs = 0;
}
} else
apply_ifs = 1;
switch (subtype) {
case VSLENGTH:
expdest = cvtnum(varlen, expdest);
break;
case VSNORMAL:
break;
case VSPLUS:
set = !set;
/* FALLTHROUGH */
case VSMINUS:
if (!set) {
argstr(p, flag | (apply_ifs ? EXP_IFS_SPLIT : 0));
/*
* ${x-a b c} doesn't get split, but removing the
* 'apply_ifs = 0' apparently breaks ${1+"$@"}..
* ${x-'a b' c} should generate 2 args.
*/
if (*p != CTLENDVAR)
/* We should have marked stuff already */
apply_ifs = 0;
}
break;
case VSTRIMLEFT:
case VSTRIMLEFTMAX:
case VSTRIMRIGHT:
case VSTRIMRIGHTMAX:
if (!set) {
set = 1; /* allow argbackq to be advanced if needed */
break;
}
/*
* Terminate the string and start recording the pattern
* right after it
*/
STPUTC('\0', expdest);
patloc = expdest - stackblock();
if (subevalvar_trim(p, patloc, subtype, startloc, varflags,
quotes) == 0) {
int amount = (expdest - stackblock() - patloc) + 1;
STADJUST(-amount, expdest);
}
/* Remove any recorded regions beyond start of variable */
removerecordregions(startloc);
apply_ifs = 1;
break;
case VSASSIGN:
case VSQUESTION:
if (set)
break;
if (subevalvar(p, var, subtype, startloc, varflags)) {
/* if subevalvar() returns, it always returns 1 */
varflags &= ~VSNUL;
/*
* Remove any recorded regions beyond
* start of variable
*/
removerecordregions(startloc);
goto again;
}
apply_ifs = 0;
break;
default:
abort();
}
#if 0
p[-1] = '='; /* recover overwritten '=' */
#endif
if (apply_ifs)
recordregion(startloc, expdest - stackblock(),
varflags & VSQUOTE);
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(const 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 == 0)
ap = arg0;
else if (num > shellparam.nparam)
return 0;
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(const char *name, int quoted, int subtype, int flag)
{
int num;
char *p;
int i;
char sep;
char **ap;
char const *syntax;
if (subtype == VSLENGTH) /* no magic required ... */
flag &= ~EXP_FULL;
#define STRTODEST(p) \
do {\
if (flag & (EXP_GLOB | EXP_CASE) && subtype != VSLENGTH) { \
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;
break;
case '?':
num = exitstatus;
break;
case '#':
num = shellparam.nparam;
break;
case '!':
num = backgndpid;
break;
case '-':
for (i = 0; i < option_flags; i++) {
if (optlist[optorder[i]].val)
STPUTC(optlist[optorder[i]].letter, expdest);
}
return;
case '@':
if (flag & EXP_SPLIT && quoted) {
for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
STRTODEST(p);
if (*ap)
/* A NUL separates args inside "" */
STPUTC('\0', expdest);
}
return;
}
/* fall through */
case '*':
sep = ifsval()[0];
for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
STRTODEST(p);
if (!*ap)
break;
if (sep)
STPUTC(sep, expdest);
else if ((flag & (EXP_SPLIT|EXP_IN_QUOTES)) == EXP_SPLIT
&& !quoted && **ap != '\0')
STPUTC('\0', expdest);
}
return;
default:
if (is_digit(*name)) {
long lnum;
errno = 0;
lnum = strtol(name, &p, 10);
if (errno != 0 || (*p != '\0' && *p != '='))
return;
if (lnum == 0)
p = arg0;
else if (lnum > 0 && lnum <= shellparam.nparam)
p = shellparam.p[lnum - 1];
else
return;
STRTODEST(p);
}
return;
}
/*
* only the specials with an int value arrive here
*/
expdest = cvtnum(num, expdest);
}
/*
* Record the fact that we have to scan this region of the
* string for IFS characters.
*/
STATIC void
recordregion(int start, int end, int inquotes)
{
struct ifsregion *ifsp;
VTRACE(DBG_EXPAND, ("recordregion(%d,%d,%d)\n", start, end, inquotes));
if (ifslastp == NULL) {
ifsp = &ifsfirst;
} else {
if (ifslastp->endoff == start
&& ifslastp->inquotes == inquotes) {
/* extend previous area */
ifslastp->endoff = end;
return;
}
ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
ifslastp->next = ifsp;
}
ifslastp = ifsp;
ifslastp->next = NULL;
ifslastp->begoff = start;
ifslastp->endoff = end;
ifslastp->inquotes = inquotes;
}
/*
* 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;
const char *ifs;
const char *ifsspc;
int had_param_ch = 0;
start = string;
VTRACE(DBG_EXPAND, ("ifsbreakup(\"%s\")", string)); /* misses \0's */
if (ifslastp == NULL) {
/* Return entire argument, IFS doesn't apply to any of it */
VTRACE(DBG_EXPAND, ("no regions\n", string));
sp = stalloc(sizeof(*sp));
sp->text = start;
*arglist->lastp = sp;
arglist->lastp = &sp->next;
return;
}
ifs = ifsval();
for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) {
p = string + ifsp->begoff;
VTRACE(DBG_EXPAND, (" !%.*s!(%d)", ifsp->endoff-ifsp->begoff,
p, ifsp->endoff-ifsp->begoff));
while (p < string + ifsp->endoff) {
had_param_ch = 1;
q = p;
if (*p == CTLESC)
p++;
if (ifsp->inquotes) {
/* Only NULs (should be from "$@") end args */
if (*p != 0) {
p++;
continue;
}
ifsspc = NULL;
VTRACE(DBG_EXPAND, (" \\0 nxt:\"%s\" ", p));
} else {
if (!strchr(ifs, *p)) {
p++;
continue;
}
had_param_ch = 0;
ifsspc = strchr(" \t\n", *p);
/* Ignore IFS whitespace at start */
if (q == start && ifsspc != NULL) {
p++;
start = p;
continue;
}
}
/* Save this argument... */
*q = '\0';
VTRACE(DBG_EXPAND, ("<%s>", start));
sp = stalloc(sizeof(*sp));
sp->text = start;
*arglist->lastp = sp;
arglist->lastp = &sp->next;
p++;
if (ifsspc != NULL) {
/* Ignore further trailing IFS whitespace */
for (; p < string + ifsp->endoff; p++) {
q = p;
if (*p == CTLESC)
p++;
if (strchr(ifs, *p) == NULL) {
p = q;
break;
}
if (strchr(" \t\n", *p) == NULL) {
p++;
break;
}
}
}
start = p;
}
}
/*
* Save anything left as an argument.
* Traditionally we have treated 'IFS=':'; set -- x$IFS' as
* generating 2 arguments, the second of which is empty.
* Some recent clarification of the Posix spec say that it
* should only generate one....
*/
if (had_param_ch || *start != 0) {
VTRACE(DBG_EXPAND, (" T<%s>", start));
sp = stalloc(sizeof(*sp));
sp->text = start;
*arglist->lastp = sp;
arglist->lastp = &sp->next;
}
VTRACE(DBG_EXPAND, ("\n"));
}
STATIC void
ifsfree(void)
{
while (ifsfirst.next != NULL) {
struct ifsregion *ifsp;
INTOFF;
ifsp = ifsfirst.next->next;
ckfree(ifsfirst.next);
ifsfirst.next = ifsp;
INTON;
}
ifslastp = NULL;
ifsfirst.next = NULL;
}
/*
* Expand shell metacharacters. At this point, the only control characters
* should be escapes. The results are stored in the list exparg.
*/
char *expdir;
STATIC void
expandmeta(struct strlist *str, int flag)
{
char *p;
struct strlist **savelastp;
struct strlist *sp;
char c;
/* TODO - EXP_REDIR */
while (str) {
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;
}
}
STATIC void
add_args(struct strlist *str)
{
while (str) {
*exparg.lastp = str;
rmescapes(str->text);
exparg.lastp = &str->next;
str = str->next;
}
}
/*
* Do metacharacter (i.e. *, ?, [...]) expansion.
*/
STATIC void
expmeta(char *enddir, char *name)
{
char *p;
const char *cp;
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++;
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) {
cp = ".";
} else if (enddir == expdir + 1 && *expdir == '/') {
cp = "/";
} else {
cp = expdir;
enddir[-1] = '\0';
}
if ((dirp = opendir(cp)) == 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, cp = dp->d_name;
(*p++ = *cp++) != '\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 = 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;
}
/*
* See if a character matches a character class, starting at the first colon
* of "[:class:]".
* If a valid character class is recognized, a pointer to the next character
* after the final closing bracket is stored into *end, otherwise a null
* pointer is stored into *end.
*/
static int
match_charclass(const char *p, wchar_t chr, const char **end)
{
char name[20];
char *nameend;
wctype_t cclass;
*end = NULL;
p++;
nameend = strstr(p, ":]");
if (nameend == NULL || (size_t)(nameend - p) >= sizeof(name) ||
nameend == p)
return 0;
memcpy(name, p, nameend - p);
name[nameend - p] = '\0';
*end = nameend + 2;
cclass = wctype(name);
/* An unknown class matches nothing but is valid nevertheless. */
if (cclass == 0)
return 0;
return iswctype(chr, cclass);
}
/*
* Returns true if the pattern matches the string.
*/
STATIC int
patmatch(const char *pattern, const char *string, int squoted)
{
const char *p, *q, *end;
const char *bt_p, *bt_q;
char c;
wchar_t wc, wc2;
p = pattern;
q = string;
bt_p = NULL;
bt_q = NULL;
for (;;) {
switch (c = *p++) {
case '\0':
if (*q != '\0')
goto backtrack;
return 1;
case CTLESC:
if (squoted && *q == CTLESC)
q++;
if (*q++ != *p++)
goto backtrack;
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++;
}
}
/*
* First try the shortest match for the '*' that
* could work. We can forget any earlier '*' since
* there is no way having it match more characters
* can help us, given that we are already here.
*/
bt_p = p;
bt_q = q;
break;
case '[': {
const char *savep, *saveq, *endp;
int invert, found;
unsigned char chr;
endp = p;
if (*endp == '!')
endp++;
for (;;) {
while (*endp == CTLQUOTEMARK)
endp++;
if (*endp == '\0')
goto dft; /* no matching ] */
if (*endp == CTLESC)
endp++;
if (*++endp == ']')
break;
}
invert = 0;
savep = p, saveq = q;
invert = 0;
if (*p == '!' || *p == '^') {
invert++;
p++;
}
found = 0;
if (*q == '\0')
return 0;
chr = (unsigned char)*q++;
c = *p++;
do {
if (c == CTLQUOTEMARK)
continue;
if (c == '\0') {
p = savep, q = saveq;
c = '[';
goto dft;
}
if (c == '[' && *p == ':') {
found |= match_charclass(p, chr, &end);
if (end != NULL)
p = end;
}
if (c == CTLESC)
c = *p++;
wc = (unsigned char)c;
if (*p == '-' && p[1] != ']') {
p++;
if (*p == CTLESC)
p++;
wc2 = (unsigned char)*p++;
if ( collate_range_cmp(chr, wc) >= 0
&& collate_range_cmp(chr, wc2) <= 0
)
found = 1;
} else {
if (chr == wc)
found = 1;
}
} while ((c = *p++) != ']');
if (found == invert)
goto backtrack;
break;
}
dft: default:
if (squoted && *q == CTLESC)
q++;
if (*q++ == c)
break;
backtrack:
/*
* If we have a mismatch (other than hitting the end
* of the string), go back to the last '*' seen and
* have it match one additional character.
*/
if (bt_p == NULL)
return 0;
if (*bt_q == '\0')
return 0;
bt_q++;
p = bt_p;
q = bt_q;
break;
}
}
}
/*
* 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(). Assumes result buffer is on the stack
*/
STATIC char *
cvtnum(int num, char *buf)
{
char temp[32];
int neg = num < 0;
char *p = temp + sizeof temp - 1;
if (neg)
num = -num;
*p = '\0';
do {
*--p = num % 10 + '0';
} while ((num /= 10) != 0 && p > temp + 1);
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("%d", argc - 1);
out1c('\0');
for (i = 1, len = 0; i < argc; i++)
len += strlen(argv[i]);
out1fmt("%zu", len);
out1c('\0');
for (i = 1; i < argc; i++) {
out1str(argv[i]);
out1c('\0');
}
return (0);
}