scoutos / prex-0.9.0 / usr / bin / sh / var.c @ 03e9c04a
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/*
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* Copyright (c) 2009, Kohsuke Ohtani
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* All rights reserved.
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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. Neither the name of the author nor the names of any co-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 AUTHOR 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 AUTHOR 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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#include <unistd.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <stdio.h> |
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#include <errno.h> |
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extern char **environ; |
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/*
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* Shell variables.
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*/
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#define VTABSIZE 20 |
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#define MAXVARNAME 32 |
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struct var {
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char *name;
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char *val;
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}; |
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static struct var vartab[VTABSIZE]; |
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static int |
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is_name(char c)
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{ |
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if ((c >= 'a' && c <= 'z') || |
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(c >= 'A' && c <= 'Z') || c == '_') |
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return 1; |
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return 0; |
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} |
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static int |
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is_validname(char *name)
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{ |
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char *p;
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for (p = name; *p != '\0'; p++) { |
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if (!is_name(*p))
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return 0; |
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} |
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return 1; |
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} |
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static struct var * |
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lookupvar(char *name)
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{ |
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struct var *var;
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int i;
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var = &vartab[0];
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for (i = 0; i < VTABSIZE; i++) { |
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if (var->name != NULL && !strcmp(var->name, name)) |
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return var;
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var++; |
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} |
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return NULL; |
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} |
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void
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setvar(char *name, char *val) |
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{ |
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struct var *var, *free;
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int i;
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/*
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* Lookup existing name in variable table.
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*/
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var = lookupvar(name); |
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if (var == NULL) { |
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/*
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* Not found. Find empty slot.
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*/
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free = NULL;
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var = &vartab[0];
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for (i = 0; i < VTABSIZE; i++) { |
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if (var->name == NULL) { |
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free = var; |
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break;
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} |
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var++; |
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} |
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if (free == NULL) { |
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fprintf(stderr, "too many variables\n");
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return;
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} |
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var = free; |
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} |
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if (!is_validname(name)) {
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fprintf(stderr, "%s: bad vairable name\n", name);
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return;
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} |
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if ((var->name = strdup(name)) == NULL) { |
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fprintf(stderr, "out of memory\n");
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return;
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} |
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var->val = strdup(val); |
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} |
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void
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unsetvar(char *name)
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{ |
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struct var *var;
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/* Find target slot in variable table */
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var = lookupvar(name); |
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if (var == NULL) |
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return;
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free(var->name); |
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free(var->val); |
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var->name = NULL;
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var->val = NULL;
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} |
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void
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setvareq(char *str)
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{ |
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char name[MAXVARNAME];
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char *p, *s;
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int i;
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s = str; |
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p = name; |
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for (i = 0; i < MAXVARNAME - 1; i++) { |
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*p++ = *s++; |
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if (*s == '=') |
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break;
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} |
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*p = '\0';
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p = strchr(str, '=');
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setvar(name, p + 1);
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} |
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int
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cmd_showvars(int argc, char *argv[]) |
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{ |
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struct var *var;
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int i;
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var = &vartab[0];
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for (i = 0; i < VTABSIZE; i++) { |
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if (var->name != NULL) |
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printf("%s=%s\n", var->name, var->val);
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var++; |
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} |
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return 0; |
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} |
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int
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cmd_unsetvar(int argc, char *argv[]) |
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{ |
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if (argc != 2) { |
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fprintf(stderr, "usage: unset name\n");
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return 0; |
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} |
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unsetvar(argv[1]);
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return 0; |
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} |
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int
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cmd_export(int argc, char *argv[]) |
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{ |
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struct var *var;
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int i;
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if (argc == 1) { |
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fprintf(stderr, "usage: export name\n");
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return 0; |
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} |
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for (i = 1; i < argc; i++) { |
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var = lookupvar(argv[i]); |
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if (var != NULL) |
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setenv(var->name, var->val, 1);
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} |
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return 0; |
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} |
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void
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initvar(void)
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{ |
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char **envp;
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int i;
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for (i = 0; i < VTABSIZE; i++) |
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vartab[i].name = NULL;
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for (envp = environ; *envp; envp++) {
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if (strchr(*envp, '=')) |
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setvareq(*envp); |
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} |
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} |