vars.c
/*
* Copyright (c) 1980, 1993
* The Regents of the University of California. All rights reserved.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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
static char sccsid[] = "@(#)vars.c 8.1 (Berkeley) 6/6/93";
#endif /* not lint */
#include "rcv.h"
#include "extern.h"
/*
* Mail -- a mail program
*
* Variable handling stuff.
*/
/*
* Assign a value to a variable.
*/
void
assign(name, value)
char name[], value[];
{
register struct var *vp;
register int h;
h = hash(name);
vp = lookup(name);
if (vp == NOVAR) {
vp = (struct var *) calloc(sizeof *vp, 1);
vp->v_name = vcopy(name);
vp->v_link = variables[h];
variables[h] = vp;
}
else
vfree(vp->v_value);
vp->v_value = vcopy(value);
}
/*
* Free up a variable string. We do not bother to allocate
* strings whose value is "" since they are expected to be frequent.
* Thus, we cannot free same!
*/
void
vfree(cp)
char *cp;
{
if (*cp)
free(cp);
}
/*
* Copy a variable value into permanent (ie, not collected after each
* command) space. Do not bother to alloc space for ""
*/
char *
vcopy(str)
char str[];
{
char *new;
unsigned len;
if (*str == '\0')
return "";
len = strlen(str) + 1;
if ((new = malloc(len)) == NULL)
panic("Out of memory");
bcopy(str, new, (int) len);
return new;
}
/*
* Get the value of a variable and return it.
* Look in the environment if its not available locally.
*/
char *
value(name)
char name[];
{
register struct var *vp;
if ((vp = lookup(name)) == NOVAR)
return(getenv(name));
return(vp->v_value);
}
/*
* Locate a variable and return its variable
* node.
*/
struct var *
lookup(name)
register char name[];
{
register struct var *vp;
for (vp = variables[hash(name)]; vp != NOVAR; vp = vp->v_link)
if (*vp->v_name == *name && equal(vp->v_name, name))
return(vp);
return(NOVAR);
}
/*
* Locate a group name and return it.
*/
struct grouphead *
findgroup(name)
register char name[];
{
register struct grouphead *gh;
for (gh = groups[hash(name)]; gh != NOGRP; gh = gh->g_link)
if (*gh->g_name == *name && equal(gh->g_name, name))
return(gh);
return(NOGRP);
}
/*
* Print a group out on stdout
*/
void
printgroup(name)
char name[];
{
register struct grouphead *gh;
register struct group *gp;
if ((gh = findgroup(name)) == NOGRP) {
printf("\"%s\": not a group\n", name);
return;
}
printf("%s\t", gh->g_name);
for (gp = gh->g_list; gp != NOGE; gp = gp->ge_link)
printf(" %s", gp->ge_name);
putchar('\n');
}
/*
* Hash the passed string and return an index into
* the variable or group hash table.
*/
int
hash(name)
register char *name;
{
register h = 0;
while (*name) {
h <<= 2;
h += *name++;
}
if (h < 0 && (h = -h) < 0)
h = 0;
return (h % HSHSIZE);
}