652 lines
13 KiB
C
Executable File
652 lines
13 KiB
C
Executable File
/*-
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* Copyright (c) 1991 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Kenneth Almquist.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef lint
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static char sccsid[] = "@(#)var.c 5.3 (Berkeley) 4/12/91";
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#endif /* not lint */
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/*
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* Shell variables.
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*/
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#include "shell.h"
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#include "output.h"
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#include "expand.h"
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#include "nodes.h" /* for other headers */
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#include "eval.h" /* defines cmdenviron */
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#include "exec.h"
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#include "syntax.h"
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#include "options.h"
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#include "mail.h"
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#include "var.h"
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#include "memalloc.h"
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#include "error.h"
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#include "mystring.h"
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#define VTABSIZE 39
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struct varinit {
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struct var *var;
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int flags;
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char *text;
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};
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#if ATTY
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struct var vatty;
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#endif
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struct var vifs;
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struct var vmail;
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struct var vmpath;
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struct var vpath;
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struct var vps1;
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struct var vps2;
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struct var vpse;
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struct var vvers;
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#if ATTY
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struct var vterm;
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#endif
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const struct varinit varinit[] = {
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#if ATTY
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{&vatty, VSTRFIXED|VTEXTFIXED|VUNSET, "ATTY="},
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#endif
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{&vifs, VSTRFIXED|VTEXTFIXED, "IFS= \t\n"},
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{&vmail, VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL="},
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{&vmpath, VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH="},
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{&vpath, VSTRFIXED|VTEXTFIXED, "PATH=:/bin:/usr/bin"},
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/*
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* vps1 depends on uid
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*/
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{&vps2, VSTRFIXED|VTEXTFIXED, "PS2=> "},
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{&vpse, VSTRFIXED|VTEXTFIXED, "PSE=* "},
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#if ATTY
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{&vterm, VSTRFIXED|VTEXTFIXED|VUNSET, "TERM="},
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#endif
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{NULL, 0, NULL}
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};
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struct var *vartab[VTABSIZE];
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STATIC void unsetvar __P((char *));
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STATIC struct var **hashvar __P((char *));
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STATIC int varequal __P((char *, char *));
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/*
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* Initialize the varable symbol tables and import the environment
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*/
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#ifdef mkinit
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INCLUDE "var.h"
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INIT {
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char **envp;
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extern char **environ;
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initvar();
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for (envp = environ ; *envp ; envp++) {
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if (strchr(*envp, '=')) {
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setvareq(*envp, VEXPORT|VTEXTFIXED);
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}
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}
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}
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#endif
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/*
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* This routine initializes the builtin variables. It is called when the
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* shell is initialized and again when a shell procedure is spawned.
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*/
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void
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initvar() {
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const struct varinit *ip;
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struct var *vp;
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struct var **vpp;
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for (ip = varinit ; (vp = ip->var) != NULL ; ip++) {
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if ((vp->flags & VEXPORT) == 0) {
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vpp = hashvar(ip->text);
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vp->next = *vpp;
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*vpp = vp;
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vp->text = ip->text;
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vp->flags = ip->flags;
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}
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}
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/*
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* PS1 depends on uid
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*/
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if ((vps1.flags & VEXPORT) == 0) {
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vpp = hashvar("PS1=");
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vps1.next = *vpp;
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*vpp = &vps1;
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vps1.text = getuid() ? "PS1=$ " : "PS1=# ";
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vps1.flags = VSTRFIXED|VTEXTFIXED;
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}
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}
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/*
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* Set the value of a variable. The flags argument is ored with the
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* flags of the variable. If val is NULL, the variable is unset.
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*/
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void
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setvar(name, val, flags)
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char *name, *val;
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{
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char *p, *q;
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int len;
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int namelen;
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char *nameeq;
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int isbad;
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isbad = 0;
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p = name;
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if (! is_name(*p++))
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isbad = 1;
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for (;;) {
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if (! is_in_name(*p)) {
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if (*p == '\0' || *p == '=')
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break;
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isbad = 1;
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}
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p++;
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}
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namelen = p - name;
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if (isbad)
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error("%.*s: is read only", namelen, name);
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len = namelen + 2; /* 2 is space for '=' and '\0' */
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if (val == NULL) {
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flags |= VUNSET;
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} else {
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len += strlen(val);
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}
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p = nameeq = ckmalloc(len);
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q = name;
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while (--namelen >= 0)
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*p++ = *q++;
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*p++ = '=';
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*p = '\0';
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if (val)
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scopy(val, p);
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setvareq(nameeq, flags);
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}
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/*
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* Same as setvar except that the variable and value are passed in
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* the first argument as name=value. Since the first argument will
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* be actually stored in the table, it should not be a string that
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* will go away.
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*/
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void
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setvareq(s, flags)
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char *s;
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{
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struct var *vp, **vpp;
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vpp = hashvar(s);
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for (vp = *vpp ; vp ; vp = vp->next) {
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if (varequal(s, vp->text)) {
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if (vp->flags & VREADONLY) {
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int len = strchr(s, '=') - s;
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error("%.*s: is read only", len, s);
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}
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INTOFF;
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if (vp == &vpath)
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changepath(s + 5); /* 5 = strlen("PATH=") */
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if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
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ckfree(vp->text);
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vp->flags &=~ (VTEXTFIXED|VSTACK|VUNSET);
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vp->flags |= flags;
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vp->text = s;
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if (vp == &vmpath || (vp == &vmail && ! mpathset()))
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chkmail(1);
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INTON;
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return;
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}
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}
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/* not found */
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vp = ckmalloc(sizeof (*vp));
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vp->flags = flags;
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vp->text = s;
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vp->next = *vpp;
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*vpp = vp;
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}
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/*
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* Process a linked list of variable assignments.
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*/
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void
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listsetvar(list)
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struct strlist *list;
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{
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struct strlist *lp;
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INTOFF;
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for (lp = list ; lp ; lp = lp->next) {
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setvareq(savestr(lp->text), 0);
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}
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INTON;
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}
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/*
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* Find the value of a variable. Returns NULL if not set.
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*/
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char *
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lookupvar(name)
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char *name;
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{
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struct var *v;
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for (v = *hashvar(name) ; v ; v = v->next) {
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if (varequal(v->text, name)) {
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if (v->flags & VUNSET)
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return NULL;
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return strchr(v->text, '=') + 1;
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}
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}
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return NULL;
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}
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/*
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* Search the environment of a builtin command. If the second argument
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* is nonzero, return the value of a variable even if it hasn't been
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* exported.
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*/
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char *
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bltinlookup(name, doall)
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char *name;
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{
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struct strlist *sp;
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struct var *v;
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for (sp = cmdenviron ; sp ; sp = sp->next) {
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if (varequal(sp->text, name))
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return strchr(sp->text, '=') + 1;
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}
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for (v = *hashvar(name) ; v ; v = v->next) {
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if (varequal(v->text, name)) {
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if (v->flags & VUNSET
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|| ! doall && (v->flags & VEXPORT) == 0)
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return NULL;
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return strchr(v->text, '=') + 1;
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}
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}
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return NULL;
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}
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/*
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* Generate a list of exported variables. This routine is used to construct
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* the third argument to execve when executing a program.
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*/
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char **
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environment() {
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int nenv;
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struct var **vpp;
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struct var *vp;
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char **env, **ep;
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nenv = 0;
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for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
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for (vp = *vpp ; vp ; vp = vp->next)
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if (vp->flags & VEXPORT)
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nenv++;
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}
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ep = env = stalloc((nenv + 1) * sizeof *env);
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for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
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for (vp = *vpp ; vp ; vp = vp->next)
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if (vp->flags & VEXPORT)
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*ep++ = vp->text;
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}
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*ep = NULL;
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return env;
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}
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/*
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* Called when a shell procedure is invoked to clear out nonexported
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* variables. It is also necessary to reallocate variables of with
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* VSTACK set since these are currently allocated on the stack.
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*/
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#ifdef mkinit
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MKINIT void shprocvar();
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SHELLPROC {
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shprocvar();
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}
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#endif
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void
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shprocvar() {
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struct var **vpp;
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struct var *vp, **prev;
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for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
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for (prev = vpp ; (vp = *prev) != NULL ; ) {
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if ((vp->flags & VEXPORT) == 0) {
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*prev = vp->next;
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if ((vp->flags & VTEXTFIXED) == 0)
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ckfree(vp->text);
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if ((vp->flags & VSTRFIXED) == 0)
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ckfree(vp);
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} else {
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if (vp->flags & VSTACK) {
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vp->text = savestr(vp->text);
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vp->flags &=~ VSTACK;
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}
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prev = &vp->next;
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}
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}
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}
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initvar();
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}
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/*
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* Command to list all variables which are set. Currently this command
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* is invoked from the set command when the set command is called without
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* any variables.
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*/
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int
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showvarscmd(argc, argv) char **argv; {
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struct var **vpp;
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struct var *vp;
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for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
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for (vp = *vpp ; vp ; vp = vp->next) {
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if ((vp->flags & VUNSET) == 0)
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out1fmt("%s\n", vp->text);
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}
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}
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return 0;
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}
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/*
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* The export and readonly commands.
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*/
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int
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exportcmd(argc, argv) char **argv; {
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struct var **vpp;
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struct var *vp;
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char *name;
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char *p;
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int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
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listsetvar(cmdenviron);
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if (argc > 1) {
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while ((name = *argptr++) != NULL) {
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if ((p = strchr(name, '=')) != NULL) {
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p++;
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} else {
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vpp = hashvar(name);
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for (vp = *vpp ; vp ; vp = vp->next) {
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if (varequal(vp->text, name)) {
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vp->flags |= flag;
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goto found;
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}
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}
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}
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setvar(name, p, flag);
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found:;
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}
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} else {
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for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
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for (vp = *vpp ; vp ; vp = vp->next) {
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if (vp->flags & flag) {
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for (p = vp->text ; *p != '=' ; p++)
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out1c(*p);
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out1c('\n');
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}
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}
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}
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}
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return 0;
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}
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/*
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* The "local" command.
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*/
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localcmd(argc, argv) char **argv; {
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char *name;
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if (! in_function())
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error("Not in a function");
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while ((name = *argptr++) != NULL) {
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mklocal(name);
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}
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return 0;
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}
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/*
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* Make a variable a local variable. When a variable is made local, it's
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* value and flags are saved in a localvar structure. The saved values
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* will be restored when the shell function returns. We handle the name
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* "-" as a special case.
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*/
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void
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mklocal(name)
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char *name;
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{
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struct localvar *lvp;
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struct var **vpp;
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struct var *vp;
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INTOFF;
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lvp = ckmalloc(sizeof (struct localvar));
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if (name[0] == '-' && name[1] == '\0') {
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lvp->text = ckmalloc(sizeof optval);
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bcopy(optval, lvp->text, sizeof optval);
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vp = NULL;
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} else {
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vpp = hashvar(name);
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for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next);
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if (vp == NULL) {
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if (strchr(name, '='))
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setvareq(savestr(name), VSTRFIXED);
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else
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setvar(name, NULL, VSTRFIXED);
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vp = *vpp; /* the new variable */
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lvp->text = NULL;
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lvp->flags = VUNSET;
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} else {
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lvp->text = vp->text;
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lvp->flags = vp->flags;
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vp->flags |= VSTRFIXED|VTEXTFIXED;
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if (strchr(name, '='))
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setvareq(savestr(name), 0);
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}
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}
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lvp->vp = vp;
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lvp->next = localvars;
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localvars = lvp;
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INTON;
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}
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/*
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* Called after a function returns.
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*/
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void
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poplocalvars() {
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struct localvar *lvp;
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struct var *vp;
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while ((lvp = localvars) != NULL) {
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localvars = lvp->next;
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vp = lvp->vp;
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if (vp == NULL) { /* $- saved */
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bcopy(lvp->text, optval, sizeof optval);
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ckfree(lvp->text);
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} else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
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unsetvar(vp->text);
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} else {
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if ((vp->flags & VTEXTFIXED) == 0)
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ckfree(vp->text);
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vp->flags = lvp->flags;
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vp->text = lvp->text;
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}
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ckfree(lvp);
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}
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}
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setvarcmd(argc, argv) char **argv; {
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if (argc <= 2)
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return unsetcmd(argc, argv);
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else if (argc == 3)
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setvar(argv[1], argv[2], 0);
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else
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error("List assignment not implemented");
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return 0;
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}
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/*
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* The unset builtin command. We unset the function before we unset the
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* variable to allow a function to be unset when there is a readonly variable
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* with the same name.
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*/
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unsetcmd(argc, argv) char **argv; {
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char **ap;
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for (ap = argv + 1 ; *ap ; ap++) {
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unsetfunc(*ap);
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unsetvar(*ap);
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|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* Unset the specified variable.
|
|
*/
|
|
|
|
STATIC void
|
|
unsetvar(s)
|
|
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)) {
|
|
INTOFF;
|
|
if (*(strchr(vp->text, '=') + 1) != '\0'
|
|
|| vp->flags & VREADONLY) {
|
|
setvar(s, nullstr, 0);
|
|
}
|
|
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;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Find the appropriate entry in the hash table from the name.
|
|
*/
|
|
|
|
STATIC struct var **
|
|
hashvar(p)
|
|
register char *p;
|
|
{
|
|
unsigned int hashval;
|
|
|
|
hashval = *p << 4;
|
|
while (*p && *p != '=')
|
|
hashval += *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(p, q)
|
|
register char *p, *q;
|
|
{
|
|
while (*p == *q++) {
|
|
if (*p++ == '=')
|
|
return 1;
|
|
}
|
|
if (*p == '=' && *(q - 1) == '\0')
|
|
return 1;
|
|
return 0;
|
|
}
|