1 files changed, 125 insertions, 0 deletions
diff --git a/42sh/src/utils/env.c b/42sh/src/utils/env.c
new file mode 100644
index 0000000..e3095a4
--- /dev/null
+++ b/42sh/src/utils/env.c
@@ -0,0 +1,125 @@
+#define _DEFAULT_SOURCE
+#define _POSIX_C_SOURCE 200809L
+
+#include "utils/env.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "utils/libstring.h"
+
+void env_set(const char *name, const char *value)
+{
+    if (setenv(name, value, 1) == -1)
+    {
+        fprintf(stderr, "env_set: unable to set \'%s\'=\'%s\'.\n", name, value);
+    }
+}
+
+void env_unset(const char *name)
+{
+    if (unsetenv(name) == -1)
+    {
+        fprintf(stderr, "env_unset: unable to unset \'%s\'.\n", name);
+    }
+}
+
+static void _generate_random(void)
+{
+    int d = rand() % MAX_RAND;
+    char buf[16] = { 0 };
+    sprintf(buf, "%d", d);
+    env_set("RANDOM", buf);
+}
+
+static struct string *_cat_args(void)
+{
+    int nb_args = atoi(env_get("#"));
+    struct string *s = string_create(NULL);
+    for (int i = 1; i <= nb_args; i++)
+    {
+        char buf[16] = { 0 };
+        sprintf(buf, "%d", i);
+        string_pushstr(s, env_get(buf));
+        if (i != nb_args)
+        {
+            string_pushc(s, ' ');
+        }
+    }
+    return s;
+}
+
+char *env_get(const char *name)
+{
+    if (STRINGS_ARE_EQUAL(name, "RANDOM"))
+    {
+        _generate_random();
+    }
+    if (STRINGS_ARE_EQUAL(name, "*"))
+    {
+        struct string *s = _cat_args();
+        env_set("*", s->data);
+        string_free(s);
+    }
+    if (STRINGS_ARE_EQUAL(name, "@"))
+    {
+        struct string *s = string_create(NULL);
+        string_pushc(s, '\"');
+        struct string *args = _cat_args();
+        string_pushstr(s, args->data);
+        string_pushc(s, '\"');
+        if (s->length > 2)
+        {
+            env_set("@", s->data);
+        }
+        string_free(s);
+        string_free(args);
+    }
+    return getenv(name);
+}
+
+void env_clear(void)
+{
+    if (clearenv())
+    {
+        fprintf(stderr, "env_clear: unable to clear the environment.\n");
+    }
+}
+
+static void _set_pwd(void)
+{
+    char buf[MAX_PATH_SIZE] = { 0 };
+    char *path = getcwd(buf, MAX_PATH_SIZE);
+    env_set("PWD", path);
+    env_set("OLDPWD", path);
+}
+
+static void _set_uid(void)
+{
+    uid_t uid = getuid();
+    // Magic value but UID is an integer (POSIX requirement)
+    // So it won't be more that 10 chars long
+    char buf[16] = { 0 };
+    sprintf(buf, "%u", uid);
+    env_set("UID", buf);
+}
+
+static void _set_pid(void)
+{
+    pid_t pid = getpid();
+    // Magic value but PID is an integer (POSIX requirement)
+    // So it won't be more that 10 chars long
+    char buf[16] = { 0 };
+    sprintf(buf, "%d", pid);
+    env_set("$", buf);
+}
+
+void env_setup(void)
+{
+    _set_pwd();
+    _set_uid();
+    _set_pid();
+    env_set("IFS", DEFAULT_IFS);
+    env_set("?", "0");
+}