7 files changed, 178 insertions, 0 deletions
diff --git a/src/env/__environ.c b/src/env/__environ.c
new file mode 100644
index 0000000..d7bd5e5
--- /dev/null
+++ b/src/env/__environ.c
@@ -0,0 +1,7 @@
+#include "libc.h"
+
+#undef environ
+char **___environ = 0;
+weak_alias(___environ, __environ);
+weak_alias(___environ, _environ);
+weak_alias(___environ, environ);
diff --git a/src/env/__libc_start_main.c b/src/env/__libc_start_main.c
new file mode 100644
index 0000000..70af77b
--- /dev/null
+++ b/src/env/__libc_start_main.c
@@ -0,0 +1,26 @@
+#include "libc.h"
+
+/* Any use of __environ/environ will override this symbol. */
+char **__dummy_environ = (void *)-1;
+weak_alias(__dummy_environ, ___environ);
+
+int __libc_start_main(
+	int (*main)(int, char **, char **), int argc, char **argv,
+	int (*init)(int, char **, char **), void (*fini)(void),
+	void (*ldso_fini)(void))
+{
+	/* Save the environment if it may be used by libc/application */
+	char **envp = argv+argc+1;
+	if (___environ != (void *)-1) ___environ = envp;
+
+	/* Avoid writing 0 and triggering unnecessary COW */
+	if (ldso_fini) libc.ldso_fini = ldso_fini;
+	if (fini) libc.fini = fini;
+
+	/* Execute constructors (static) linked into the application */
+	if (init) init(argc, argv, envp);
+
+	/* Pass control to to application */
+	exit(main(argc, argv, envp));
+	return 0;
+}
diff --git a/src/env/clearenv.c b/src/env/clearenv.c
new file mode 100644
index 0000000..a2475ce
--- /dev/null
+++ b/src/env/clearenv.c
@@ -0,0 +1,9 @@
+#include <stdlib.h>
+
+extern char **__environ;
+
+int clearenv()
+{
+	__environ[0] = 0;
+	return 0;
+}
diff --git a/src/env/getenv.c b/src/env/getenv.c
new file mode 100644
index 0000000..00c1bce
--- /dev/null
+++ b/src/env/getenv.c
@@ -0,0 +1,14 @@
+#include <stdlib.h>
+#include <string.h>
+#include "libc.h"
+
+char *getenv(const char *name)
+{
+	int i;
+	size_t l = strlen(name);
+	if (!__environ || !*name || strchr(name, '=')) return NULL;
+	for (i=0; __environ[i] && (strncmp(name, __environ[i], l)
+		|| __environ[i][l] != '='); i++);
+	if (__environ[i]) return __environ[i] + l+1;
+	return NULL;
+}
diff --git a/src/env/putenv.c b/src/env/putenv.c
new file mode 100644
index 0000000..181a418
--- /dev/null
+++ b/src/env/putenv.c
@@ -0,0 +1,59 @@
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <stdio.h>
+
+extern char **__environ;
+char **__env_map;
+
+int __putenv(char *s, int a)
+{
+	int i=0, j=0;
+	char *end = strchr(s, '=');
+	size_t l = end-s+1;
+	char **newenv = 0;
+	char **newmap = 0;
+	static char **oldenv;
+	
+	if (!end || l == 1) return -1;
+	for (; __environ[i] && memcmp(s, __environ[i], l); i++);
+	if (a) {
+		if (!__env_map) {
+			__env_map = calloc(2, sizeof(char *));
+			if (__env_map) __env_map[0] = s;
+		} else {
+			for (; __env_map[j] && __env_map[j] != __environ[i]; j++);
+			if (!__env_map[j]) {
+				newmap = realloc(__env_map, sizeof(char *)*(j+2));
+				if (newmap) {
+					__env_map = newmap;
+					__env_map[j] = s;
+					__env_map[j+1] = NULL;
+				}
+			} else {
+				free(__env_map[j]);
+			}
+		}
+	}
+	if (!__environ[i]) {
+		newenv = malloc(sizeof(char *)*(i+2));
+		if (!newenv) {
+			if (a && __env_map) __env_map[j] = 0;
+			return -1;
+		}
+		memcpy(newenv, __environ, sizeof(char *)*i);
+		newenv[i] = s;
+		newenv[i+1] = 0;
+		__environ = newenv;
+		free(oldenv);
+		oldenv = __environ;
+	}
+
+	__environ[i] = s;
+	return 0;
+}
+
+int putenv(char *s)
+{
+	return __putenv(s, 0);
+}
diff --git a/src/env/setenv.c b/src/env/setenv.c
new file mode 100644
index 0000000..03e165c
--- /dev/null
+++ b/src/env/setenv.c
@@ -0,0 +1,31 @@
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+int __putenv(char *s, int a);
+
+int setenv(const char *var, const char *value, int overwrite)
+{
+	char *s;
+	int l1, l2;
+
+	if (strchr(var, '=')) {
+		errno = EINVAL;
+		return -1;
+	}
+	if (!overwrite && getenv(var)) return 0;
+
+	l1 = strlen(var);
+	l2 = strlen(value);
+	s = malloc(l1+l2+2);
+	memcpy(s, var, l1);
+	s[l1] = '=';
+	memcpy(s+l1+1, value, l2);
+	s[l1+l2+1] = 0;
+	if (__putenv(s, 1)) {
+		free(s);
+		errno = ENOMEM;
+		return -1;
+	}
+	return 0;
+}
diff --git a/src/env/unsetenv.c b/src/env/unsetenv.c
new file mode 100644
index 0000000..7493d97
--- /dev/null
+++ b/src/env/unsetenv.c
@@ -0,0 +1,32 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+extern char **__environ;
+extern char **__env_map;
+
+int unsetenv(const char *name)
+{
+	int i, j;
+	size_t l = strlen(name);
+
+	if (!*name || strchr(name, '=')) {
+		errno = EINVAL;
+		return -1;
+	}
+again:
+	for (i=0; __environ[i] && (memcmp(name, __environ[i], l) || __environ[i][l] != '='); i++);
+	if (__environ[i]) {
+		if (__env_map) {
+			for (j=0; __env_map[j] && __env_map[j] != __environ[i]; j++);
+			free (__env_map[j]);
+			for (; __env_map[j]; j++)
+				__env_map[j] = __env_map[j+1];
+		}
+		for (; __environ[i]; i++)
+			__environ[i] = __environ[i+1];
+		goto again;
+	}
+	return 0;
+}