FreeBSD-5.3/bin/sh/var.c
/*-
* 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[] = "@(#)var.c 8.3 (Berkeley) 5/4/95";
#endif
#endif /* not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/bin/sh/var.c,v 1.26.2.1 2004/09/30 04:41:55 des Exp $");
#include <unistd.h>
#include <stdlib.h>
#include <paths.h>
/*
* Shell variables.
*/
#include <locale.h>
#include "shell.h"
#include "output.h"
#include "expand.h"
#include "nodes.h" /* for other headers */
#include "eval.h" /* defines cmdenviron */
#include "exec.h"
#include "syntax.h"
#include "options.h"
#include "mail.h"
#include "var.h"
#include "memalloc.h"
#include "error.h"
#include "mystring.h"
#include "parser.h"
#ifndef NO_HISTORY
#include "myhistedit.h"
#endif
#define VTABSIZE 39
struct varinit {
struct var *var;
int flags;
char *text;
void (*func)(const char *);
};
#ifndef NO_HISTORY
struct var vhistsize;
#endif
struct var vifs;
struct var vmail;
struct var vmpath;
struct var vpath;
struct var vppid;
struct var vps1;
struct var vps2;
struct var vvers;
STATIC struct var voptind;
STATIC const struct varinit varinit[] = {
#ifndef NO_HISTORY
{ &vhistsize, VSTRFIXED|VTEXTFIXED|VUNSET, "HISTSIZE=",
sethistsize },
#endif
{ &vifs, VSTRFIXED|VTEXTFIXED, "IFS= \t\n",
NULL },
{ &vmail, VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL=",
NULL },
{ &vmpath, VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH=",
NULL },
{ &vpath, VSTRFIXED|VTEXTFIXED, "PATH=" _PATH_DEFPATH,
changepath },
{ &vppid, VSTRFIXED|VTEXTFIXED|VUNSET, "PPID=",
NULL },
/*
* vps1 depends on uid
*/
{ &vps2, VSTRFIXED|VTEXTFIXED, "PS2=> ",
NULL },
{ &voptind, VSTRFIXED|VTEXTFIXED, "OPTIND=1",
getoptsreset },
{ NULL, 0, NULL,
NULL }
};
STATIC struct var *vartab[VTABSIZE];
STATIC struct var **hashvar(char *);
STATIC int varequal(char *, char *);
STATIC int localevar(char *);
/*
* Initialize the varable symbol tables and import the environment
*/
#ifdef mkinit
INCLUDE "var.h"
INIT {
char **envp;
extern char **environ;
initvar();
for (envp = environ ; *envp ; envp++) {
if (strchr(*envp, '=')) {
setvareq(*envp, VEXPORT|VTEXTFIXED);
}
}
}
#endif
/*
* This routine initializes the builtin variables. It is called when the
* shell is initialized and again when a shell procedure is spawned.
*/
void
initvar(void)
{
char ppid[20];
const struct varinit *ip;
struct var *vp;
struct var **vpp;
for (ip = varinit ; (vp = ip->var) != NULL ; ip++) {
if ((vp->flags & VEXPORT) == 0) {
vpp = hashvar(ip->text);
vp->next = *vpp;
*vpp = vp;
vp->text = ip->text;
vp->flags = ip->flags;
vp->func = ip->func;
}
}
/*
* PS1 depends on uid
*/
if ((vps1.flags & VEXPORT) == 0) {
vpp = hashvar("PS1=");
vps1.next = *vpp;
*vpp = &vps1;
vps1.text = geteuid() ? "PS1=$ " : "PS1=# ";
vps1.flags = VSTRFIXED|VTEXTFIXED;
}
if ((vppid.flags & VEXPORT) == 0) {
fmtstr(ppid, sizeof(ppid), "%d", (int)getppid());
setvarsafe("PPID", ppid, 0);
}
}
/*
* Safe version of setvar, returns 1 on success 0 on failure.
*/
int
setvarsafe(char *name, char *val, int flags)
{
struct jmploc jmploc;
struct jmploc *volatile savehandler = handler;
int err = 0;
#if __GNUC__
/* Avoid longjmp clobbering */
(void) &err;
#endif
if (setjmp(jmploc.loc))
err = 1;
else {
handler = &jmploc;
setvar(name, val, flags);
}
handler = savehandler;
return err;
}
/*
* Set the value of a variable. The flags argument is tored with the
* flags of the variable. If val is NULL, the variable is unset.
*/
void
setvar(char *name, char *val, int flags)
{
char *p, *q;
int len;
int namelen;
char *nameeq;
int isbad;
isbad = 0;
p = name;
if (! is_name(*p))
isbad = 1;
p++;
for (;;) {
if (! is_in_name(*p)) {
if (*p == '\0' || *p == '=')
break;
isbad = 1;
}
p++;
}
namelen = p - name;
if (isbad)
error("%.*s: bad variable name", namelen, name);
len = namelen + 2; /* 2 is space for '=' and '\0' */
if (val == NULL) {
flags |= VUNSET;
} else {
len += strlen(val);
}
p = nameeq = ckmalloc(len);
q = name;
while (--namelen >= 0)
*p++ = *q++;
*p++ = '=';
*p = '\0';
if (val)
scopy(val, p);
setvareq(nameeq, flags);
}
STATIC int
localevar(char *s)
{
static char *lnames[7] = {
"ALL", "COLLATE", "CTYPE", "MONETARY",
"NUMERIC", "TIME", NULL
};
char **ss;
if (*s != 'L')
return 0;
if (varequal(s + 1, "ANG"))
return 1;
if (strncmp(s + 1, "C_", 2) != 0)
return 0;
for (ss = lnames; *ss ; ss++)
if (varequal(s + 3, *ss))
return 1;
return 0;
}
/*
* Same as setvar except that the variable and value are passed in
* the first argument as name=value. Since the first argument will
* be actually stored in the table, it should not be a string that
* will go away.
*/
void
setvareq(char *s, int flags)
{
struct var *vp, **vpp;
int len;
if (aflag)
flags |= VEXPORT;
vpp = hashvar(s);
for (vp = *vpp ; vp ; vp = vp->next) {
if (varequal(s, vp->text)) {
if (vp->flags & VREADONLY) {
len = strchr(s, '=') - s;
error("%.*s: is read only", len, s);
}
INTOFF;
if (vp->func && (flags & VNOFUNC) == 0)
(*vp->func)(strchr(s, '=') + 1);
if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
ckfree(vp->text);
vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET);
vp->flags |= flags;
vp->text = s;
/*
* We could roll this to a function, to handle it as
* a regular variable function callback, but why bother?
*/
if (vp == &vmpath || (vp == &vmail && ! mpathset()))
chkmail(1);
if ((vp->flags & VEXPORT) && localevar(s)) {
putenv(s);
(void) setlocale(LC_ALL, "");
}
INTON;
return;
}
}
/* not found */
vp = ckmalloc(sizeof (*vp));
vp->flags = flags;
vp->text = s;
vp->next = *vpp;
vp->func = NULL;
INTOFF;
*vpp = vp;
if ((vp->flags & VEXPORT) && localevar(s)) {
putenv(s);
(void) setlocale(LC_ALL, "");
}
INTON;
}
/*
* Process a linked list of variable assignments.
*/
void
listsetvar(struct strlist *list)
{
struct strlist *lp;
INTOFF;
for (lp = list ; lp ; lp = lp->next) {
setvareq(savestr(lp->text), 0);
}
INTON;
}
/*
* Find the value of a variable. Returns NULL if not set.
*/
char *
lookupvar(char *name)
{
struct var *v;
for (v = *hashvar(name) ; v ; v = v->next) {
if (varequal(v->text, name)) {
if (v->flags & VUNSET)
return NULL;
return strchr(v->text, '=') + 1;
}
}
return NULL;
}
/*
* Search the environment of a builtin command. If the second argument
* is nonzero, return the value of a variable even if it hasn't been
* exported.
*/
char *
bltinlookup(char *name, int doall)
{
struct strlist *sp;
struct var *v;
for (sp = cmdenviron ; sp ; sp = sp->next) {
if (varequal(sp->text, name))
return strchr(sp->text, '=') + 1;
}
for (v = *hashvar(name) ; v ; v = v->next) {
if (varequal(v->text, name)) {
if ((v->flags & VUNSET)
|| (!doall && (v->flags & VEXPORT) == 0))
return NULL;
return strchr(v->text, '=') + 1;
}
}
return NULL;
}
/*
* Generate a list of exported variables. This routine is used to construct
* the third argument to execve when executing a program.
*/
char **
environment(void)
{
int nenv;
struct var **vpp;
struct var *vp;
char **env, **ep;
nenv = 0;
for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
for (vp = *vpp ; vp ; vp = vp->next)
if (vp->flags & VEXPORT)
nenv++;
}
ep = env = stalloc((nenv + 1) * sizeof *env);
for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
for (vp = *vpp ; vp ; vp = vp->next)
if (vp->flags & VEXPORT)
*ep++ = vp->text;
}
*ep = NULL;
return env;
}
/*
* Called when a shell procedure is invoked to clear out nonexported
* variables. It is also necessary to reallocate variables of with
* VSTACK set since these are currently allocated on the stack.
*/
#ifdef mkinit
MKINIT void shprocvar();
SHELLPROC {
shprocvar();
}
#endif
void
shprocvar(void)
{
struct var **vpp;
struct var *vp, **prev;
for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
for (prev = vpp ; (vp = *prev) != NULL ; ) {
if ((vp->flags & VEXPORT) == 0) {
*prev = vp->next;
if ((vp->flags & VTEXTFIXED) == 0)
ckfree(vp->text);
if ((vp->flags & VSTRFIXED) == 0)
ckfree(vp);
} else {
if (vp->flags & VSTACK) {
vp->text = savestr(vp->text);
vp->flags &=~ VSTACK;
}
prev = &vp->next;
}
}
}
initvar();
}
/*
* Command to list all variables which are set. Currently this command
* is invoked from the set command when the set command is called without
* any variables.
*/
int
showvarscmd(int argc __unused, char **argv __unused)
{
struct var **vpp;
struct var *vp;
const char *s;
for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
for (vp = *vpp ; vp ; vp = vp->next) {
if (vp->flags & VUNSET)
continue;
for (s = vp->text; *s != '='; s++)
out1c(*s);
out1c('=');
out1qstr(s + 1);
out1c('\n');
}
}
return 0;
}
/*
* The export and readonly commands.
*/
int
exportcmd(int argc, char **argv)
{
struct var **vpp;
struct var *vp;
char *name;
char *p;
char *cmdname;
int ch, values;
int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
cmdname = argv[0];
optreset = optind = 1;
opterr = 0;
values = 0;
while ((ch = getopt(argc, argv, "p")) != -1) {
switch (ch) {
case 'p':
values = 1;
break;
case '?':
default:
error("unknown option: -%c", optopt);
}
}
argc -= optind;
argv += optind;
listsetvar(cmdenviron);
if (argc != 0) {
while ((name = *argptr++) != NULL) {
if ((p = strchr(name, '=')) != NULL) {
p++;
} else {
vpp = hashvar(name);
for (vp = *vpp ; vp ; vp = vp->next) {
if (varequal(vp->text, name)) {
vp->flags |= flag;
if ((vp->flags & VEXPORT) && localevar(vp->text)) {
putenv(vp->text);
(void) setlocale(LC_ALL, "");
}
goto found;
}
}
}
setvar(name, p, flag);
found:;
}
} else {
for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
for (vp = *vpp ; vp ; vp = vp->next) {
if (vp->flags & flag) {
if (values) {
out1str(cmdname);
out1c(' ');
}
for (p = vp->text ; *p != '=' ; p++)
out1c(*p);
if (values && !(vp->flags & VUNSET)) {
out1c('=');
out1qstr(p + 1);
}
out1c('\n');
}
}
}
}
return 0;
}
/*
* The "local" command.
*/
int
localcmd(int argc __unused, char **argv __unused)
{
char *name;
if (! in_function())
error("Not in a function");
while ((name = *argptr++) != NULL) {
mklocal(name);
}
return 0;
}
/*
* Make a variable a local variable. When a variable is made local, it's
* value and flags are saved in a localvar structure. The saved values
* will be restored when the shell function returns. We handle the name
* "-" as a special case.
*/
void
mklocal(char *name)
{
struct localvar *lvp;
struct var **vpp;
struct var *vp;
INTOFF;
lvp = ckmalloc(sizeof (struct localvar));
if (name[0] == '-' && name[1] == '\0') {
lvp->text = ckmalloc(sizeof optlist);
memcpy(lvp->text, optlist, sizeof optlist);
vp = NULL;
} else {
vpp = hashvar(name);
for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next);
if (vp == NULL) {
if (strchr(name, '='))
setvareq(savestr(name), VSTRFIXED);
else
setvar(name, NULL, VSTRFIXED);
vp = *vpp; /* the new variable */
lvp->text = NULL;
lvp->flags = VUNSET;
} else {
lvp->text = vp->text;
lvp->flags = vp->flags;
vp->flags |= VSTRFIXED|VTEXTFIXED;
if (strchr(name, '='))
setvareq(savestr(name), 0);
}
}
lvp->vp = vp;
lvp->next = localvars;
localvars = lvp;
INTON;
}
/*
* Called after a function returns.
*/
void
poplocalvars(void)
{
struct localvar *lvp;
struct var *vp;
while ((lvp = localvars) != NULL) {
localvars = lvp->next;
vp = lvp->vp;
if (vp == NULL) { /* $- saved */
memcpy(optlist, lvp->text, sizeof optlist);
ckfree(lvp->text);
} else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
(void)unsetvar(vp->text);
} else {
if ((vp->flags & VTEXTFIXED) == 0)
ckfree(vp->text);
vp->flags = lvp->flags;
vp->text = lvp->text;
}
ckfree(lvp);
}
}
int
setvarcmd(int argc, char **argv)
{
if (argc <= 2)
return unsetcmd(argc, argv);
else if (argc == 3)
setvar(argv[1], argv[2], 0);
else
error("List assignment not implemented");
return 0;
}
/*
* The unset builtin command. We unset the function before we unset the
* variable to allow a function to be unset when there is a readonly variable
* with the same name.
*/
int
unsetcmd(int argc __unused, char **argv __unused)
{
char **ap;
int i;
int flg_func = 0;
int flg_var = 0;
int ret = 0;
while ((i = nextopt("vf")) != '\0') {
if (i == 'f')
flg_func = 1;
else
flg_var = 1;
}
if (flg_func == 0 && flg_var == 0)
flg_var = 1;
for (ap = argptr; *ap ; ap++) {
if (flg_func)
ret |= unsetfunc(*ap);
if (flg_var)
ret |= unsetvar(*ap);
}
return ret;
}
/*
* Unset the specified variable.
*/
int
unsetvar(char *s)
{
struct var **vpp;
struct var *vp;
vpp = hashvar(s);
for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) {
if (varequal(vp->text, s)) {
if (vp->flags & VREADONLY)
return (1);
INTOFF;
if (*(strchr(vp->text, '=') + 1) != '\0')
setvar(s, nullstr, 0);
if ((vp->flags & VEXPORT) && localevar(vp->text)) {
unsetenv(s);
setlocale(LC_ALL, "");
}
vp->flags &= ~VEXPORT;
vp->flags |= VUNSET;
if ((vp->flags & VSTRFIXED) == 0) {
if ((vp->flags & VTEXTFIXED) == 0)
ckfree(vp->text);
*vpp = vp->next;
ckfree(vp);
}
INTON;
return (0);
}
}
return (0);
}
/*
* Find the appropriate entry in the hash table from the name.
*/
STATIC struct var **
hashvar(char *p)
{
unsigned int hashval;
hashval = ((unsigned char) *p) << 4;
while (*p && *p != '=')
hashval += (unsigned char) *p++;
return &vartab[hashval % VTABSIZE];
}
/*
* Returns true if the two strings specify the same varable. The first
* variable name is terminated by '='; the second may be terminated by
* either '=' or '\0'.
*/
STATIC int
varequal(char *p, char *q)
{
while (*p == *q++) {
if (*p++ == '=')
return 1;
}
if (*p == '=' && *(q - 1) == '\0')
return 1;
return 0;
}