44 lines
768 B
C
Executable File
44 lines
768 B
C
Executable File
#pragma ident "@(#)getenv.c 1.3 92/07/20 SMI" /* from S5R2 1.2 */
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/*LINTLIBRARY*/
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/*
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* getenv(name)
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* returns ptr to value associated with name, if any, else NULL
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*/
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#define NULL 0
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extern char **environ;
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static char *nvmatch();
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char *
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getenv(name)
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register char *name;
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{
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register char *v, **p=environ;
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if(p == NULL)
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return(NULL);
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while(*p != NULL)
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if((v = nvmatch(name, *p++)) != NULL)
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return(v);
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return(NULL);
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}
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/*
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* s1 is either name, or name=value
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* s2 is name=value
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* if names match, return value of s2, else NULL
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* used for environment searching: see getenv
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*/
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static char *
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nvmatch(s1, s2)
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register char *s1, *s2;
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{
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while(*s1 == *s2++)
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if(*s1++ == '=')
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return(s2);
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if(*s1 == '\0' && *(s2-1) == '=')
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return(s2);
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return(NULL);
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}
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