3 * putenv.c -- (un)set an envariable
7 * This code is Copyright (c) 2002, by the authors of nmh. See the
8 * COPYRIGHT file in the root directory of the nmh distribution for
9 * complete copyright information.
14 extern char **environ;
19 int m_putenv (char *, char *);
20 int unputenv (char *);
21 static int nvmatch (char *, char *);
25 m_putenv (char *name, char *value)
28 register char **ep, **nep, *cp;
30 if (!(cp = malloc ((size_t) (strlen (name) + strlen (value) + 2))))
33 sprintf (cp, "%s=%s", name, value);
35 for (ep = environ, i = 0; *ep; ep++, i++)
36 if (nvmatch (name, *ep)) {
41 if (!(nep = (char **) malloc ((size_t) ((i + 2) * sizeof(*nep)))))
44 for (ep = environ, i = 0; *ep; nep[i++] = *ep++)
58 for (ep = environ; *ep; ep++)
59 if (nvmatch (name, *ep))
64 for (nep = ep + 1; *nep; nep++)
73 nvmatch (char *s1, char *s2)
79 return (*s1 == '\0' && *--s2 == '=');