freebsd-dev/bin/sh/var.c
Jilles Tjoelker 8ef0ae8a8f sh: Make struct arglist an array instead of a linked list.
This simplifies the code (e.g. allowing use of qsort(3) instead of a
hand-rolled mergesort) and should have better cache properties.

The waste of unused args arrays after resizes is approximately the same as
the savings from getting rid of the next pointers.

At the same time, remove a piece of global state and move some duplicated
code into a function.
2015-10-11 21:33:00 +00:00

955 lines
18 KiB
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("$FreeBSD$");
#include <unistd.h>
#include <stdlib.h>
#include <paths.h>
/*
* Shell variables.
*/
#include <locale.h>
#include <langinfo.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"
#include "builtins.h"
#ifndef NO_HISTORY
#include "myhistedit.h"
#endif
#define VTABSIZE 39
struct varinit {
struct var *var;
int flags;
const char *text;
void (*func)(const char *);
};
#ifndef NO_HISTORY
struct var vhistsize;
struct var vterm;
#endif
struct var vifs;
struct var vmail;
struct var vmpath;
struct var vpath;
struct var vps1;
struct var vps2;
struct var vps4;
static struct var voptind;
struct var vdisvfork;
struct localvar *localvars;
int forcelocal;
static const struct varinit varinit[] = {
#ifndef NO_HISTORY
{ &vhistsize, VUNSET, "HISTSIZE=",
sethistsize },
#endif
{ &vifs, 0, "IFS= \t\n",
NULL },
{ &vmail, VUNSET, "MAIL=",
NULL },
{ &vmpath, VUNSET, "MAILPATH=",
NULL },
{ &vpath, 0, "PATH=" _PATH_DEFPATH,
changepath },
/*
* vps1 depends on uid
*/
{ &vps2, 0, "PS2=> ",
NULL },
{ &vps4, 0, "PS4=+ ",
NULL },
#ifndef NO_HISTORY
{ &vterm, VUNSET, "TERM=",
setterm },
#endif
{ &voptind, 0, "OPTIND=1",
getoptsreset },
{ &vdisvfork, VUNSET, "SH_DISABLE_VFORK=",
NULL },
{ NULL, 0, NULL,
NULL }
};
static struct var *vartab[VTABSIZE];
static const char *const locale_names[7] = {
"LC_COLLATE", "LC_CTYPE", "LC_MONETARY",
"LC_NUMERIC", "LC_TIME", "LC_MESSAGES", NULL
};
static const int locale_categories[7] = {
LC_COLLATE, LC_CTYPE, LC_MONETARY, LC_NUMERIC, LC_TIME, LC_MESSAGES, 0
};
static int varequal(const char *, const char *);
static struct var *find_var(const char *, struct var ***, int *);
static int localevar(const char *);
static void setvareq_const(const char *s, int flags);
extern char **environ;
/*
* This routine initializes the builtin variables and imports the environment.
* It is called when the shell is initialized.
*/
void
initvar(void)
{
char ppid[20];
const struct varinit *ip;
struct var *vp;
struct var **vpp;
char **envp;
for (ip = varinit ; (vp = ip->var) != NULL ; ip++) {
if (find_var(ip->text, &vpp, &vp->name_len) != NULL)
continue;
vp->next = *vpp;
*vpp = vp;
vp->text = __DECONST(char *, ip->text);
vp->flags = ip->flags | VSTRFIXED | VTEXTFIXED;
vp->func = ip->func;
}
/*
* PS1 depends on uid
*/
if (find_var("PS1", &vpp, &vps1.name_len) == NULL) {
vps1.next = *vpp;
*vpp = &vps1;
vps1.text = __DECONST(char *, geteuid() ? "PS1=$ " : "PS1=# ");
vps1.flags = VSTRFIXED|VTEXTFIXED;
}
fmtstr(ppid, sizeof(ppid), "%d", (int)getppid());
setvarsafe("PPID", ppid, 0);
for (envp = environ ; *envp ; envp++) {
if (strchr(*envp, '=')) {
setvareq(*envp, VEXPORT|VTEXTFIXED);
}
}
setvareq_const("OPTIND=1", 0);
}
/*
* Safe version of setvar, returns 1 on success 0 on failure.
*/
int
setvarsafe(const char *name, const char *val, int flags)
{
struct jmploc jmploc;
struct jmploc *const savehandler = handler;
int err = 0;
int inton;
inton = is_int_on();
if (setjmp(jmploc.loc))
err = 1;
else {
handler = &jmploc;
setvar(name, val, flags);
}
handler = savehandler;
SETINTON(inton);
return err;
}
/*
* Set the value of a variable. The flags argument is stored with the
* flags of the variable. If val is NULL, the variable is unset.
*/
void
setvar(const char *name, const char *val, int flags)
{
const char *p;
size_t len;
size_t namelen;
size_t vallen;
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", (int)namelen, name);
len = namelen + 2; /* 2 is space for '=' and '\0' */
if (val == NULL) {
flags |= VUNSET;
vallen = 0;
} else {
vallen = strlen(val);
len += vallen;
}
INTOFF;
nameeq = ckmalloc(len);
memcpy(nameeq, name, namelen);
nameeq[namelen] = '=';
if (val)
memcpy(nameeq + namelen + 1, val, vallen + 1);
else
nameeq[namelen + 1] = '\0';
setvareq(nameeq, flags);
INTON;
}
static int
localevar(const char *s)
{
const char *const *ss;
if (*s != 'L')
return 0;
if (varequal(s + 1, "ANG"))
return 1;
if (strncmp(s + 1, "C_", 2) != 0)
return 0;
if (varequal(s + 3, "ALL"))
return 1;
for (ss = locale_names; *ss ; ss++)
if (varequal(s + 3, *ss + 3))
return 1;
return 0;
}
/*
* Sets/unsets an environment variable from a pointer that may actually be a
* pointer into environ where the string should not be manipulated.
*/
static void
change_env(const char *s, int set)
{
char *eqp;
char *ss;
INTOFF;
ss = savestr(s);
if ((eqp = strchr(ss, '=')) != NULL)
*eqp = '\0';
if (set && eqp != NULL)
(void) setenv(ss, eqp + 1, 1);
else
(void) unsetenv(ss);
ckfree(ss);
INTON;
return;
}
/*
* 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 nlen;
if (aflag)
flags |= VEXPORT;
if (forcelocal && !(flags & (VNOSET | VNOLOCAL)))
mklocal(s);
vp = find_var(s, &vpp, &nlen);
if (vp != NULL) {
if (vp->flags & VREADONLY) {
if ((flags & (VTEXTFIXED|VSTACK)) == 0)
ckfree(s);
error("%.*s: is read only", vp->name_len, s);
}
if (flags & VNOSET) {
if ((flags & (VTEXTFIXED|VSTACK)) == 0)
ckfree(s);
return;
}
INTOFF;
if (vp->func && (flags & VNOFUNC) == 0)
(*vp->func)(s + vp->name_len + 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?
*
* Note: this assumes iflag is not set to 1 initially.
* As part of initvar(), this is called before arguments
* are looked at.
*/
if ((vp == &vmpath || (vp == &vmail && ! mpathset())) &&
iflag == 1)
chkmail(1);
if ((vp->flags & VEXPORT) && localevar(s)) {
change_env(s, 1);
(void) setlocale(LC_ALL, "");
updatecharset();
}
INTON;
return;
}
/* not found */
if (flags & VNOSET) {
if ((flags & (VTEXTFIXED|VSTACK)) == 0)
ckfree(s);
return;
}
INTOFF;
vp = ckmalloc(sizeof (*vp));
vp->flags = flags;
vp->text = s;
vp->name_len = nlen;
vp->next = *vpp;
vp->func = NULL;
*vpp = vp;
if ((vp->flags & VEXPORT) && localevar(s)) {
change_env(s, 1);
(void) setlocale(LC_ALL, "");
updatecharset();
}
INTON;
}
static void
setvareq_const(const char *s, int flags)
{
setvareq(__DECONST(char *, s), flags | VTEXTFIXED);
}
/*
* Process a linked list of variable assignments.
*/
void
listsetvar(struct arglist *list, int flags)
{
int i;
INTOFF;
for (i = 0; i < list->count; i++)
setvareq(savestr(list->args[i]), flags);
INTON;
}
/*
* Find the value of a variable. Returns NULL if not set.
*/
char *
lookupvar(const char *name)
{
struct var *v;
v = find_var(name, NULL, NULL);
if (v == NULL || v->flags & VUNSET)
return NULL;
return v->text + v->name_len + 1;
}
/*
* 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(const char *name, int doall)
{
struct var *v;
char *result;
int i;
result = NULL;
if (cmdenviron) for (i = 0; i < cmdenviron->count; i++) {
if (varequal(cmdenviron->args[i], name))
result = strchr(cmdenviron->args[i], '=') + 1;
}
if (result != NULL)
return result;
v = find_var(name, NULL, NULL);
if (v == NULL || v->flags & VUNSET ||
(!doall && (v->flags & VEXPORT) == 0))
return NULL;
return v->text + v->name_len + 1;
}
/*
* Set up locale for a builtin (LANG/LC_* assignments).
*/
void
bltinsetlocale(void)
{
int act = 0;
char *loc, *locdef;
int i;
if (cmdenviron) for (i = 0; i < cmdenviron->count; i++) {
if (localevar(cmdenviron->args[i])) {
act = 1;
break;
}
}
if (!act)
return;
loc = bltinlookup("LC_ALL", 0);
INTOFF;
if (loc != NULL) {
setlocale(LC_ALL, loc);
INTON;
updatecharset();
return;
}
locdef = bltinlookup("LANG", 0);
for (i = 0; locale_names[i] != NULL; i++) {
loc = bltinlookup(locale_names[i], 0);
if (loc == NULL)
loc = locdef;
if (loc != NULL)
setlocale(locale_categories[i], loc);
}
INTON;
updatecharset();
}
/*
* Undo the effect of bltinlocaleset().
*/
void
bltinunsetlocale(void)
{
int i;
INTOFF;
if (cmdenviron) for (i = 0; i < cmdenviron->count; i++) {
if (localevar(cmdenviron->args[i])) {
setlocale(LC_ALL, "");
updatecharset();
return;
}
}
INTON;
}
/*
* Update the localeisutf8 flag.
*/
void
updatecharset(void)
{
char *charset;
charset = nl_langinfo(CODESET);
localeisutf8 = !strcmp(charset, "UTF-8");
}
void
initcharset(void)
{
updatecharset();
initial_localeisutf8 = localeisutf8;
}
/*
* 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;
}
static int
var_compare(const void *a, const void *b)
{
const char *const *sa, *const *sb;
sa = a;
sb = b;
/*
* This compares two var=value strings which creates a different
* order from what you would probably expect. POSIX is somewhat
* ambiguous on what should be sorted exactly.
*/
return strcoll(*sa, *sb);
}
/*
* Command to list all variables which are set. This is invoked from the
* set command when it is called without any options or operands.
*/
int
showvarscmd(int argc __unused, char **argv __unused)
{
struct var **vpp;
struct var *vp;
const char *s;
const char **vars;
int i, n;
/*
* POSIX requires us to sort the variables.
*/
n = 0;
for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) {
for (vp = *vpp; vp; vp = vp->next) {
if (!(vp->flags & VUNSET))
n++;
}
}
INTOFF;
vars = ckmalloc(n * sizeof(*vars));
i = 0;
for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) {
for (vp = *vpp; vp; vp = vp->next) {
if (!(vp->flags & VUNSET))
vars[i++] = vp->text;
}
}
qsort(vars, n, sizeof(*vars), var_compare);
for (i = 0; i < n; i++) {
/*
* Skip improper variable names so the output remains usable as
* shell input.
*/
if (!isassignment(vars[i]))
continue;
s = strchr(vars[i], '=');
s++;
outbin(vars[i], s - vars[i], out1);
out1qstr(s);
out1c('\n');
}
ckfree(vars);
INTON;
return 0;
}
/*
* The export and readonly commands.
*/
int
exportcmd(int argc __unused, char **argv)
{
struct var **vpp;
struct var *vp;
char **ap;
char *name;
char *p;
char *cmdname;
int ch, values;
int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
cmdname = argv[0];
values = 0;
while ((ch = nextopt("p")) != '\0') {
switch (ch) {
case 'p':
values = 1;
break;
}
}
if (values && *argptr != NULL)
error("-p requires no arguments");
if (*argptr != NULL) {
for (ap = argptr; (name = *ap) != NULL; ap++) {
if ((p = strchr(name, '=')) != NULL) {
p++;
} else {
vp = find_var(name, NULL, NULL);
if (vp != NULL) {
vp->flags |= flag;
if ((vp->flags & VEXPORT) && localevar(vp->text)) {
change_env(vp->text, 1);
(void) setlocale(LC_ALL, "");
updatecharset();
}
continue;
}
}
setvar(name, p, flag);
}
} else {
for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
for (vp = *vpp ; vp ; vp = vp->next) {
if (vp->flags & flag) {
if (values) {
/*
* Skip improper variable names
* so the output remains usable
* as shell input.
*/
if (!isassignment(vp->text))
continue;
out1str(cmdname);
out1c(' ');
}
if (values && !(vp->flags & VUNSET)) {
outbin(vp->text,
vp->name_len + 1, out1);
out1qstr(vp->text +
vp->name_len + 1);
} else
outbin(vp->text, vp->name_len,
out1);
out1c('\n');
}
}
}
}
return 0;
}
/*
* The "local" command.
*/
int
localcmd(int argc __unused, char **argv __unused)
{
char *name;
nextopt("");
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 {
vp = find_var(name, &vpp, NULL);
if (vp == NULL) {
if (strchr(name, '='))
setvareq(savestr(name), VSTRFIXED | VNOLOCAL);
else
setvar(name, NULL, VSTRFIXED | VNOLOCAL);
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 (name[vp->name_len] == '=')
setvareq(savestr(name), VNOLOCAL);
}
}
lvp->vp = vp;
lvp->next = localvars;
localvars = lvp;
INTON;
}
/*
* Called after a function returns.
*/
void
poplocalvars(void)
{
struct localvar *lvp;
struct var *vp;
INTOFF;
while ((lvp = localvars) != NULL) {
localvars = lvp->next;
vp = lvp->vp;
if (vp == NULL) { /* $- saved */
memcpy(optlist, lvp->text, sizeof optlist);
ckfree(lvp->text);
optschanged();
} 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);
}
INTON;
}
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("too many arguments");
return 0;
}
/*
* The unset builtin command.
*/
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;
INTOFF;
for (ap = argptr; *ap ; ap++) {
if (flg_func)
ret |= unsetfunc(*ap);
if (flg_var)
ret |= unsetvar(*ap);
}
INTON;
return ret;
}
/*
* Unset the specified variable.
* Called with interrupts off.
*/
int
unsetvar(const char *s)
{
struct var **vpp;
struct var *vp;
vp = find_var(s, &vpp, NULL);
if (vp == NULL)
return (0);
if (vp->flags & VREADONLY)
return (1);
if (vp->text[vp->name_len + 1] != '\0')
setvar(s, "", 0);
if ((vp->flags & VEXPORT) && localevar(vp->text)) {
change_env(s, 0);
setlocale(LC_ALL, "");
updatecharset();
}
vp->flags &= ~VEXPORT;
vp->flags |= VUNSET;
if ((vp->flags & VSTRFIXED) == 0) {
if ((vp->flags & VTEXTFIXED) == 0)
ckfree(vp->text);
*vpp = vp->next;
ckfree(vp);
}
return (0);
}
/*
* Returns true if the two strings specify the same variable. The first
* variable name is terminated by '='; the second may be terminated by
* either '=' or '\0'.
*/
static int
varequal(const char *p, const char *q)
{
while (*p == *q++) {
if (*p++ == '=')
return 1;
}
if (*p == '=' && *(q - 1) == '\0')
return 1;
return 0;
}
/*
* Search for a variable.
* 'name' may be terminated by '=' or a NUL.
* vppp is set to the pointer to vp, or the list head if vp isn't found
* lenp is set to the number of characters in 'name'
*/
static struct var *
find_var(const char *name, struct var ***vppp, int *lenp)
{
unsigned int hashval;
int len;
struct var *vp, **vpp;
const char *p = name;
hashval = 0;
while (*p && *p != '=')
hashval = 2 * hashval + (unsigned char)*p++;
len = p - name;
if (lenp)
*lenp = len;
vpp = &vartab[hashval % VTABSIZE];
if (vppp)
*vppp = vpp;
for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) {
if (vp->name_len != len)
continue;
if (memcmp(vp->text, name, len) != 0)
continue;
if (vppp)
*vppp = vpp;
return vp;
}
return NULL;
}