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Annotation of prex-old/usr/lib/libc/stdlib/setenv.c, Revision 1.1.1.1

1.1       nbrk        1: /*
                      2:  * Copyright (c) 1987, 1993
                      3:  *     The Regents of the University of California.  All rights reserved.
                      4:  *
                      5:  * Redistribution and use in source and binary forms, with or without
                      6:  * modification, are permitted provided that the following conditions
                      7:  * are met:
                      8:  * 1. Redistributions of source code must retain the above copyright
                      9:  *    notice, this list of conditions and the following disclaimer.
                     10:  * 2. Redistributions in binary form must reproduce the above copyright
                     11:  *    notice, this list of conditions and the following disclaimer in the
                     12:  *    documentation and/or other materials provided with the distribution.
                     13:  * 3. Neither the name of the University nor the names of its contributors
                     14:  *    may be used to endorse or promote products derived from this software
                     15:  *    without specific prior written permission.
                     16:  *
                     17:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     18:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     19:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     20:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     21:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     22:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     23:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     24:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     25:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     26:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     27:  * SUCH DAMAGE.
                     28:  */
                     29:
                     30: #include <stddef.h>
                     31: #include <stdlib.h>
                     32: #include <string.h>
                     33:
                     34: extern char **environ;
                     35:
                     36: char *__findenv(const char *, int *);
                     37:
                     38: /*
                     39:  * setenv --
                     40:  *     Set the value of the environmental variable "name" to be
                     41:  *     "value".  If rewrite is set, replace any current value.
                     42:  */
                     43: int
                     44: setenv(name, value, rewrite)
                     45:        const char *name;
                     46:        const char *value;
                     47:        int rewrite;
                     48: {
                     49:        static int alloced;                     /* if allocated space before */
                     50:        char *c;
                     51:        int l_value, offset;
                     52:
                     53:        if (*value == '=')                      /* no `=' in value */
                     54:                ++value;
                     55:        l_value = strlen(value);
                     56:        if ((c = __findenv(name, &offset))) {   /* find if already exists */
                     57:                if (!rewrite)
                     58:                        return (0);
                     59:                if ((int)strlen(c) >= l_value) {        /* old larger; copy over */
                     60:                        while ( (*c++ = *value++) );
                     61:                        return (0);
                     62:                }
                     63:        } else {                                        /* create new slot */
                     64:                int cnt;
                     65:                char **p;
                     66:
                     67:                for (p = environ, cnt = 0; *p; ++p, ++cnt);
                     68:                if (alloced) {                  /* just increase size */
                     69:                        environ = (char **)realloc((char *)environ,
                     70:                            (size_t)(sizeof(char *) * (cnt + 2)));
                     71:                        if (!environ)
                     72:                                return (-1);
                     73:                }
                     74:                else {                          /* get new space */
                     75:                        alloced = 1;            /* copy old entries into it */
                     76:                        p = malloc((size_t)(sizeof(char *) * (cnt + 2)));
                     77:                        if (!p)
                     78:                                return (-1);
                     79:                        bcopy(environ, p, cnt * sizeof(char *));
                     80:                        environ = p;
                     81:                }
                     82:                environ[cnt + 1] = NULL;
                     83:                offset = cnt;
                     84:        }
                     85:        for (c = (char *)name; *c && *c != '='; ++c);   /* no `=' in name */
                     86:        if (!(environ[offset] =                 /* name + `=' + value */
                     87:            malloc((size_t)((int)(c - name) + l_value + 2))))
                     88:                return (-1);
                     89:        for (c = environ[offset]; (*c = *name++) && *c != '='; ++c);
                     90:        for (*c++ = '='; (*c++ = *value++) != 0;);
                     91:        return (0);
                     92: }
                     93:
                     94: /*
                     95:  * unsetenv(name) --
                     96:  *     Delete environmental variable "name".
                     97:  */
                     98: void
                     99: unsetenv(name)
                    100:        const char *name;
                    101: {
                    102:        char **p;
                    103:        int offset;
                    104:
                    105:        while (__findenv(name, &offset))        /* if set multiple times */
                    106:                for (p = &environ[offset];; ++p)
                    107:                        if (!(*p = *(p + 1)))
                    108:                                break;
                    109: }