diff options
Diffstat (limited to 'lisp/setenv.c')
| -rw-r--r-- | lisp/setenv.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/lisp/setenv.c b/lisp/setenv.c new file mode 100644 index 0000000..089ab92 --- /dev/null +++ b/lisp/setenv.c @@ -0,0 +1,178 @@ +/* $OpenBSD: setenv.c,v 1.13 2010/08/23 22:31:50 millert Exp $ */ +/* + * Copyright (c) 1987 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. 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 <errno.h> +#include <stdlib.h> +#include <string.h> + +char *__findenv(const char *name, int len, int *offset); + +extern char **environ; +static char **lastenv; /* last value of environ */ + +/* + * putenv -- + * Add a name=value string directly to the environmental, replacing + * any current value. + */ +int +putenv(char *str) +{ + char **P, *cp; + size_t cnt; + int offset = 0; + + for (cp = str; *cp && *cp != '='; ++cp) + ; + if (*cp != '=') { + errno = EINVAL; + return (-1); /* missing `=' in string */ + } + + if (__findenv(str, (int)(cp - str), &offset) != NULL) { + environ[offset++] = str; + /* could be set multiple times */ + while (__findenv(str, (int)(cp - str), &offset)) { + for (P = &environ[offset];; ++P) + if (!(*P = *(P + 1))) + break; + } + return (0); + } + + /* create new slot for string */ + for (P = environ; *P != NULL; P++) + ; + cnt = P - environ; + P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2)); + if (!P) + return (-1); + if (lastenv != environ) + memcpy(P, environ, cnt * sizeof(char *)); + lastenv = environ = P; + environ[cnt] = str; + environ[cnt + 1] = NULL; + return (0); +} + +/* + * setenv -- + * Set the value of the environmental variable "name" to be + * "value". If rewrite is set, replace any current value. + */ +int +setenv(const char *name, const char *value, int rewrite) +{ + char *C, **P; + const char *np; + int l_value, offset = 0; + + for (np = name; *np && *np != '='; ++np) + ; +#ifdef notyet + if (*np) { + errno = EINVAL; + return (-1); /* has `=' in name */ + } +#endif + + l_value = strlen(value); + if ((C = __findenv(name, (int)(np - name), &offset)) != NULL) { + int tmpoff = offset + 1; + if (!rewrite) + return (0); +#if 0 /* XXX - existing entry may not be writable */ + if (strlen(C) >= l_value) { /* old larger; copy over */ + while ((*C++ = *value++)) + ; + return (0); + } +#endif + /* could be set multiple times */ + while (__findenv(name, (int)(np - name), &tmpoff)) { + for (P = &environ[tmpoff];; ++P) + if (!(*P = *(P + 1))) + break; + } + } else { /* create new slot */ + size_t cnt; + + for (P = environ; *P != NULL; P++) + ; + cnt = P - environ; + P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2)); + if (!P) + return (-1); + if (lastenv != environ) + memcpy(P, environ, cnt * sizeof(char *)); + lastenv = environ = P; + offset = cnt; + environ[cnt + 1] = NULL; + } + if (!(environ[offset] = /* name + `=' + value */ + malloc((size_t)((int)(np - name) + l_value + 2)))) + return (-1); + for (C = environ[offset]; (*C = *name++) && *C != '='; ++C) + ; + for (*C++ = '='; (*C++ = *value++); ) + ; + return (0); +} + +/* + * unsetenv(name) -- + * Delete environmental variable "name". + */ +int +unsetenv(const char *name) +{ + char **P; + const char *np; + int offset = 0; + + if (!name || !*name) { + errno = EINVAL; + return (-1); + } + for (np = name; *np && *np != '='; ++np) + ; + if (*np) { + errno = EINVAL; + return (-1); /* has `=' in name */ + } + + /* could be set multiple times */ + while (__findenv(name, (int)(np - name), &offset)) { + for (P = &environ[offset];; ++P) + if (!(*P = *(P + 1))) + break; + } + return (0); +} |