72 lines
2.9 KiB
C
72 lines
2.9 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/alg/alg.h"
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#include "libc/mem/internal.h"
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#include "libc/mem/mem.h"
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#include "libc/runtime/runtime.h"
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#include "libc/str/str.h"
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#include "libc/sysv/errfuns.h"
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#define MAX_VARS 512
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int PutEnvImpl(char *s, bool overwrite) {
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char *p;
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unsigned i, namelen;
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p = strchr(s, '=');
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if (!p) goto fail;
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namelen = p + 1 - s;
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for (i = 0; environ[i]; ++i) {
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if (strncmp(environ[i], s, namelen) == 0) {
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if (!overwrite) {
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free(s);
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return 0;
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}
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goto replace;
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}
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}
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if (i + 1 >= MAX_VARS) goto fail;
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environ[i + 1] = NULL;
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replace:
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free(environ[i]);
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environ[i] = s;
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return 0;
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fail:
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free(s);
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return einval();
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}
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/**
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* Emplaces environment key=value.
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* @see setenv(), getenv()
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*/
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int putenv(char *string) {
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return PutEnvImpl(strdup(string), true);
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}
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textstartup static void putenv_init(void) {
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char **pin, **pout;
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pin = environ;
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pout = malloc(sizeof(char *) * MAX_VARS);
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environ = pout;
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while (*pin) *pout++ = strdup(*pin++);
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*pout = NULL;
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}
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const void *const putenv_ctor[] initarray = {putenv_init};
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