.ref-BSD-3/usr/src/libF77/getenv_.c

/*
 * getenv - f77 subroutine to return environment variables
 *
 * called by:
 *      call getenv (ENV_NAME, char_var)
 * where:
 *      ENV_NAME is the name of an environment variable
 *      char_var is a character variable which will receive
 *              the current value of ENV_NAME, or all blanks
 *              if ENV_NAME is not defined
 */

getenv_(fname, value, flen, vlen)
char *value, *fname;
long int vlen, flen;
{
extern char **environ;
register char *ep, *fp, *flast;
register char **env = environ;

flast = fname + flen;
for(fp = fname ; fp < flast ; ++fp)
        if(*fp == ' ')
                {
                flast = fp;
                break;
                }

while (ep = *env++)
        {
        for(fp = fname; fp<flast ; )
                if(*fp++ != *ep++)
                        goto endloop;

        if(*ep++ == '=')        /* copy right hand side */
                while( *ep && --vlen>=0 )
                        *value++ = *ep++;

        goto blank;

endloop: ;
        }

blank:
        while( --vlen >= 0 )
                *value++ = ' ';
return(0);
}