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Arquivotheca.SunOS-4.1.4/lib/libc/gen/common/getenv.c
seta75D ff309bfe1c Init
2021-10-11 18:37:13 -03:00

46 lines
823 B
C

#if !defined(lint) && defined(SCCSIDS)
static char sccsid[] = "@(#)getenv.c 1.1 94/10/31 SMI"; /* from S5R2 1.2 */
#endif
/*LINTLIBRARY*/
/*
* getenv(name)
* returns ptr to value associated with name, if any, else NULL
*/
#define NULL 0
extern char **environ;
static char *nvmatch();
char *
getenv(name)
register char *name;
{
register char *v, **p=environ;
if(p == NULL)
return(NULL);
while(*p != NULL)
if((v = nvmatch(name, *p++)) != NULL)
return(v);
return(NULL);
}
/*
* s1 is either name, or name=value
* s2 is name=value
* if names match, return value of s2, else NULL
* used for environment searching: see getenv
*/
static char *
nvmatch(s1, s2)
register char *s1, *s2;
{
while(*s1 == *s2++)
if(*s1++ == '=')
return(s2);
if(*s1 == '\0' && *(s2-1) == '=')
return(s2);
return(NULL);
}