xref: /freebsd/contrib/tcp_wrappers/setenv.c (revision ca987d4641cdcd7f27e153db17c5bf064934faf5)
1  /*
2   * Some systems do not have setenv(). This one is modeled after 4.4 BSD, but
3   * is implemented in terms of portable primitives only: getenv(), putenv()
4   * and malloc(). It should therefore be safe to use on every UNIX system.
5   *
6   * If clobber == 0, do not overwrite an existing variable.
7   *
8   * Returns nonzero if memory allocation fails.
9   *
10   * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
11   */
12 
13 #ifndef lint
14 static char sccsid[] = "@(#) setenv.c 1.1 93/03/07 22:47:58";
15 #endif
16 
17 /* setenv - update or insert environment (name,value) pair */
18 
19 int     setenv(name, value, clobber)
20 char   *name;
21 char   *value;
22 int     clobber;
23 {
24     char   *malloc();
25     char   *getenv();
26     char   *cp;
27 
28     if (clobber == 0 && getenv(name) != 0)
29 	return (0);
30     if ((cp = malloc(strlen(name) + strlen(value) + 2)) == 0)
31 	return (1);
32     sprintf(cp, "%s=%s", name, value);
33     return (putenv(cp));
34 }
35