Import ezmlm-idx 0.40

[ezmlm] / env.c

diff --git a/env.c b/env.c
new file mode 100644 (file)
index 0000000..05d527b
--- /dev/null
+++ b/env.c
@@ -0,0 +1,113 @@
+/* env.c, envread.c, env.h: environ library
+Daniel J. Bernstein, djb@silverton.berkeley.edu.
+Depends on str.h, alloc.h.
+Requires environ.
+19960113: rewrite. warning: interface is different.
+No known patent problems.
+*/
+
+#include "str.h"
+#include "alloc.h"
+#include "env.h"
+
+int env_isinit = 0; /* if env_isinit: */
+static int ea; /* environ is a pointer to ea+1 char*'s. */
+static int en; /* the first en of those are ALLOCATED. environ[en] is 0. */
+
+static void env_goodbye(i) int i;
+{
+ alloc_free(environ[i]);
+ environ[i] = environ[--en];
+ environ[en] = 0;
+}
+
+static char *null = 0;
+
+void env_clear()
+{
+ if (env_isinit) while (en) env_goodbye(0);
+ else environ = &null;
+}
+
+static void env_unsetlen(s,len) char *s; int len;
+{
+ int i;
+ for (i = en - 1;i >= 0;--i)
+   if (!str_diffn(s,environ[i],len))
+     if (environ[i][len] == '=')
+       env_goodbye(i);
+}
+
+int env_unset(s) char *s;
+{
+ if (!env_isinit) if (!env_init()) return 0;
+ env_unsetlen(s,str_len(s));
+ return 1;
+}
+
+static int env_add(s) char *s;
+{
+ char *t;
+ t = env_findeq(s);
+ if (t) env_unsetlen(s,t - s);
+ if (en == ea)
+  {
+   ea += 30;
+   if (!alloc_re(&environ,(en + 1) * sizeof(char *),(ea + 1) * sizeof(char *)))
+    { ea = en; return 0; }
+  }
+ environ[en++] = s;
+ environ[en] = 0;
+ return 1;
+}
+
+int env_put(s) char *s;
+{
+ char *u;
+ if (!env_isinit) if (!env_init()) return 0;
+ u = alloc(str_len(s) + 1);
+ if (!u) return 0;
+ str_copy(u,s);
+ if (!env_add(u)) { alloc_free(u); return 0; }
+ return 1;
+}
+
+int env_put2(s,t) char *s; char *t;
+{
+ char *u;
+ int slen;
+ if (!env_isinit) if (!env_init()) return 0;
+ slen = str_len(s);
+ u = alloc(slen + str_len(t) + 2);
+ if (!u) return 0;
+ str_copy(u,s);
+ u[slen] = '=';
+ str_copy(u + slen + 1,t);
+ if (!env_add(u)) { alloc_free(u); return 0; }
+ return 1;
+}
+
+int env_init()
+{
+ char **newenviron;
+ int i;
+ for (en = 0;environ[en];++en) ;
+ ea = en + 10;
+ newenviron = (char **) alloc((ea + 1) * sizeof(char *));
+ if (!newenviron) return 0;
+ for (en = 0;environ[en];++en)
+  {
+   newenviron[en] = alloc(str_len(environ[en]) + 1);
+   if (!newenviron[en])
+    {
+     for (i = 0;i < en;++i) alloc_free(newenviron[i]);
+     alloc_free(newenviron);
+     return 0;
+    }
+   str_copy(newenviron[en],environ[en]);
+  }
+ newenviron[en] = 0;
+ environ = newenviron;
+ env_isinit = 1;
+ return 1;
+}