/* $NetBSD: alias.c,v 1.12 2003/08/07 09:05:29 agc Exp $ */
/*-
* Copyright (c) 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[] = "@(#)alias.c 8.3 (Berkeley) 5/4/95";
#else
__RCSID("$NetBSD: alias.c,v 1.12 2003/08/07 09:05:29 agc Exp $");
#endif
#endif /* not lint */
#include <stdlib.h>
#include "shell.h"
#include "input.h"
#include "output.h"
#include "error.h"
#include "memalloc.h"
#include "mystring.h"
#include "alias.h"
#include "options.h" /* XXX for argptr (should remove?) */
#include "var.h"
#define ATABSIZE 39
struct alias *atab[ATABSIZE];
STATIC void setalias(char *, char *);
STATIC int unalias(char *);
STATIC struct alias **hashalias(char *);
STATIC
void
setalias(char *name, char *val)
{
struct alias *ap, **app;
app = hashalias(name);
for (ap = *app; ap; ap = ap->next) {
if (equal(name, ap->name)) {
INTOFF;
ckfree(ap->val);
ap->val = savestr(val);
INTON;
return;
}
}
/* not found */
INTOFF;
ap = ckmalloc(sizeof (struct alias));
ap->name = savestr(name);
/*
* XXX - HACK: in order that the parser will not finish reading the
* alias value off the input before processing the next alias, we
* dummy up an extra space at the end of the alias. This is a crock
* and should be re-thought. The idea (if you feel inclined to help)
* is to avoid alias recursions. The mechanism used is: when
* expanding an alias, the value of the alias is pushed back on the
* input as a string and a pointer to the alias is stored with the
* string. The alias is marked as being in use. When the input
* routine finishes reading the string, it markes the alias not
* in use. The problem is synchronization with the parser. Since
* it reads ahead, the alias is marked not in use before the
* resulting token(s) is next checked for further alias sub. The
* H A C K is that we add a little fluff after the alias value
* so that the string will not be exhausted. This is a good
* idea ------- ***NOT***
*/
#ifdef notyet
ap->val = savestr(val);
#else /* hack */
{
int len = strlen(val);
ap->val = ckmalloc(len + 2);
memcpy(ap->val, val, len);
ap->val[len] = ' '; /* fluff */
ap->val[len+1] = '\0';
}
#endif
ap->next = *app;
*app = ap;
INTON;
}
STATIC int
unalias(char *name)
{
struct alias *ap, **app;
app = hashalias(name);
for (ap = *app; ap; app = &(ap->next), ap = ap->next) {
if (equal(name, ap->name)) {
/*
* if the alias is currently in use (i.e. its
* buffer is being used by the input routine) we
* just null out the name instead of freeing it.
* We could clear it out later, but this situation
* is so rare that it hardly seems worth it.
*/
if (ap->flag & ALIASINUSE)
*ap->name = '\0';
else {
INTOFF;
*app = ap->next;
ckfree(ap->name);
ckfree(ap->val);
ckfree(ap);
INTON;
}
return (0);
}
}
return (1);
}
#ifdef mkinit
MKINIT void rmaliases(void);
SHELLPROC {
rmaliases();
}
#endif
void
rmaliases(void)
{
struct alias *ap, *tmp;
int i;
INTOFF;
for (i = 0; i < ATABSIZE; i++) {
ap = atab[i];
atab[i] = NULL;
while (ap) {
ckfree(ap->name);
ckfree(ap->val);
tmp = ap;
ap = ap->next;
ckfree(tmp);
}
}
INTON;
}
struct alias *
lookupalias(char *name, int check)
{
struct alias *ap = *hashalias(name);
for (; ap; ap = ap->next) {
if (equal(name, ap->name)) {
if (check && (ap->flag & ALIASINUSE))
return (NULL);
return (ap);
}
}
return (NULL);
}
char *
get_alias_text(char *name)
{
struct alias *ap;
ap = lookupalias(name, 0);
if (ap == NULL)
return NULL;
return ap->val;
}
/*
* TODO - sort output
*/
int
aliascmd(int argc, char **argv)
{
char *n, *v;
int ret = 0;
struct alias *ap;
if (argc == 1) {
int i;
for (i = 0; i < ATABSIZE; i++)
for (ap = atab[i]; ap; ap = ap->next) {
if (*ap->name != '\0') {
out1fmt("alias %s=", ap->name);
print_quoted(ap->val);
out1c('\n');
}
}
return (0);
}
while ((n = *++argv) != NULL) {
if ((v = strchr(n+1, '=')) == NULL) { /* n+1: funny ksh stuff */
if ((ap = lookupalias(n, 0)) == NULL) {
outfmt(out2, "alias: %s not found\n", n);
ret = 1;
} else {
out1fmt("alias %s=", n);
print_quoted(ap->val);
out1c('\n');
}
} else {
*v++ = '\0';
setalias(n, v);
}
}
return (ret);
}
int
unaliascmd(int argc, char **argv)
{
int i;
while ((i = nextopt("a")) != '\0') {
if (i == 'a') {
rmaliases();
return (0);
}
}
for (i = 0; *argptr; argptr++)
i = unalias(*argptr);
return (i);
}
STATIC struct alias **
hashalias(char *p)
{
unsigned int hashval;
hashval = *p << 4;
while (*p)
hashval+= *p++;
return &atab[hashval % ATABSIZE];
}