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![Warner Losh](/assets/img/avatar_default.png)
4 space indentation with a mix of tabs and spaces is a hassle. Update to project-standard hard-tabs with 8-space indentation in these files. This matches the new code coming in better as well.
228 lines
4.8 KiB
C
228 lines
4.8 KiB
C
/*-
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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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*
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* Jordan K. Hubbard
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* 29 August 1998
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*
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* The meat of the simple parser.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <stand.h>
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#include <string.h>
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#include "bootstrap.h"
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static void clean(void);
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static int insert(int *argcp, char *buf);
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static char *variable_lookup(char *name);
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#define PARSE_BUFSIZE 1024 /* maximum size of one element */
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#define MAXARGS 20 /* maximum number of elements */
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static char *args[MAXARGS];
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/*
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* parse: accept a string of input and "parse" it for backslash
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* substitutions and environment variable expansions (${var}),
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* returning an argc/argv style vector of whitespace separated
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* arguments. Returns 0 on success, 1 on failure (ok, ok, so I
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* wimped-out on the error codes! :).
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*
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* Note that the argv array returned must be freed by the caller, but
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* we own the space allocated for arguments and will free that on next
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* invocation. This allows argv consumers to modify the array if
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* required.
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*
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* NB: environment variables that expand to more than one whitespace
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* separated token will be returned as a single argv[] element, not
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* split in turn. Expanded text is also immune to further backslash
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* elimination or expansion since this is a one-pass, non-recursive
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* parser. You didn't specify more than this so if you want more, ask
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* me. - jkh
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*/
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#define PARSE_FAIL(expr) \
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if (expr) { \
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printf("fail at line %d\n", __LINE__); \
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clean(); \
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free(copy); \
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free(buf); \
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return 1; \
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}
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/* Accept the usual delimiters for a variable, returning counterpart */
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static char
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isdelim(int ch)
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{
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if (ch == '{')
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return '}';
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else if (ch == '(')
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return ')';
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return '\0';
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}
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static int
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isquote(int ch)
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{
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return (ch == '\'');
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}
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static int
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isdquote(int ch)
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{
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return (ch == '"');
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}
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int
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parse(int *argc, char ***argv, const char *str)
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{
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int ac;
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char *val, *p, *q, *copy = NULL;
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size_t i = 0;
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char token, tmp, quote, dquote, *buf;
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enum { STR, VAR, WHITE } state;
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ac = *argc = 0;
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dquote = quote = 0;
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if (!str || (p = copy = backslash(str)) == NULL)
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return 1;
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/* Initialize vector and state */
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clean();
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state = STR;
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buf = (char *)malloc(PARSE_BUFSIZE);
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token = 0;
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/* And awaaaaaaaaay we go! */
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while (*p) {
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switch (state) {
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case STR:
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if ((*p == '\\') && p[1]) {
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p++;
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PARSE_FAIL(i == (PARSE_BUFSIZE - 1));
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buf[i++] = *p++;
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} else if (isquote(*p)) {
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quote = quote ? 0 : *p;
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if (dquote) { /* keep quote */
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PARSE_FAIL(i == (PARSE_BUFSIZE - 1));
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buf[i++] = *p++;
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} else
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++p;
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} else if (isdquote(*p)) {
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dquote = dquote ? 0 : *p;
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if (quote) { /* keep dquote */
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PARSE_FAIL(i == (PARSE_BUFSIZE - 1));
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buf[i++] = *p++;
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} else
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++p;
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} else if (isspace(*p) && !quote && !dquote) {
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state = WHITE;
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if (i) {
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buf[i] = '\0';
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PARSE_FAIL(insert(&ac, buf));
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i = 0;
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}
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++p;
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} else if (*p == '$' && !quote) {
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token = isdelim(*(p + 1));
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if (token)
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p += 2;
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else
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++p;
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state = VAR;
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} else {
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PARSE_FAIL(i == (PARSE_BUFSIZE - 1));
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buf[i++] = *p++;
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}
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break;
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case WHITE:
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if (isspace(*p))
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++p;
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else
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state = STR;
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break;
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case VAR:
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if (token) {
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PARSE_FAIL((q = strchr(p, token)) == NULL);
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} else {
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q = p;
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while (*q && !isspace(*q))
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++q;
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}
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tmp = *q;
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*q = '\0';
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if ((val = variable_lookup(p)) != NULL) {
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size_t len = strlen(val);
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strncpy(buf + i, val, PARSE_BUFSIZE - (i + 1));
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i += min(len, PARSE_BUFSIZE - 1);
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}
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*q = tmp; /* restore value */
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p = q + (token ? 1 : 0);
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state = STR;
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break;
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}
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}
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/* missing terminating ' or " */
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PARSE_FAIL(quote || dquote);
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/* If at end of token, add it */
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if (i && state == STR) {
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buf[i] = '\0';
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PARSE_FAIL(insert(&ac, buf));
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}
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args[ac] = NULL;
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*argc = ac;
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*argv = (char **)malloc((sizeof(char *) * ac + 1));
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bcopy(args, *argv, sizeof(char *) * ac + 1);
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free(buf);
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free(copy);
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return 0;
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}
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#define MAXARGS 20
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/* Clean vector space */
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static void
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clean(void)
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{
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int i;
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for (i = 0; i < MAXARGS; i++) {
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if (args[i] != NULL) {
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free(args[i]);
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args[i] = NULL;
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}
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}
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}
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static int
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insert(int *argcp, char *buf)
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{
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if (*argcp >= MAXARGS)
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return 1;
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args[(*argcp)++] = strdup(buf);
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return 0;
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}
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static char *
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variable_lookup(char *name)
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{
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/* XXX search "special variable" space first? */
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return (char *)getenv(name);
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}
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