major refactorings

Signed-off-by: kaguya3311 <kaguya3311@national.shitposting.agency>

user/include/mlibc/helloworld.c

@@ -1,151 +1,34 @@
 #include <unistd.h>
-#include <fcntl.h>
-#include <string.h>
-#include <stddef.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <dirent.h>
+#include <sys/wait.h>
+#include <stdio.h>
 
-#define STDIN  0
-#define STDOUT 1
+int main() {
+    printf("\nforking!");
+    pid_t pid = fork();
 
-static void print(const char* s)
-{
-    write(STDOUT, s, strlen(s));
-}
-
-static void touch(const char* path)
-{
-    int fd = open(path, O_CREAT | O_WRONLY, 0644);
-    if (fd < 0) {
-        print("touch: cannot create file\n");
-        return;
+    if (pid < 0) {
+        perror("fork failed");
+        return 1;
     }
 
-    close(fd);
-}
+    if (pid == 0) {
+        // Child process
+        printf("child processed!");
+        char *argv[] = {"/bin/pwd", NULL};
+        char *envp[] = {NULL};
 
-static void ls(const char* path)
-{
-    struct dirent* entry;
+        execve("/bin/pwd", argv, envp);
 
-    DIR* dir = opendir(path ? path : ".");
-    if (!dir) {
-        print("ls: cannot open directory\n");
-        return;
+        // If execve returns, it failed
+        perror("execve failed");
+        return 1;
+    } else {
+        // Parent process
+        waitpid(pid, NULL, 0);
+        printf("Child process finished\n");
     }
 
-    while ((entry = readdir(dir)) != NULL)
-    {
-        // skip . and ..
-        if (entry->d_name[0] == '.' &&
-            (entry->d_name[1] == '\0' ||
-            (entry->d_name[1] == '.' && entry->d_name[2] == '\0')))
-            continue;
-
-        print(entry->d_name);
-        print("\n");
-    }
-
-    closedir(dir);
-}
-
-static void readline(char* buf, size_t max)
-{
-    size_t i = 0;
-
-    while (i < max - 1)
-    {
-        char c;
-        ssize_t n = read(STDIN, &c, 1);
-
-        if (n <= 0)
-            continue;
-
-        if (c == '\n')
-            break;
-
-        if (c == '\b') {
-            if (i > 0) i--;
-            continue;
-        }
-
-        buf[i++] = c;
-    }
-
-    buf[i] = '\0';
-}
-
-static void cat(const char* path)
-{
-    char buf[256];
-
-    int fd = open(path, O_RDONLY);
-    if (fd < 0) {
-        print("cat: cannot open file\n");
-        return;
-    }
-
-    ssize_t n = read(fd, buf, sizeof(buf));
-    close(fd);
-
-    if (n > 0)
-        write(STDOUT, buf, (size_t)n);
-}
-
-int main(void)
-{
-    const char* path = "/qwerty.txt";
-    const char* msg  = "Suki Suki Daisuki Kekkon Shiyo, my honey!";
-
-    char buf[128];
-
-    int fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
-    write(fd, msg, strlen(msg));
-    close(fd);
-
-    fd = open(path, O_RDONLY);
-    ssize_t n = read(fd, buf, sizeof(buf));
-    close(fd);
-
-    if (n > 0)
-        write(STDOUT, buf, (size_t)n);
-
-    char line[128];
-
-    while (1)
-    {
-        print("> ");
-        readline(line, sizeof(line));
-
-        if (strcmp(line, "exit") == 0)
-            break;
-
-        if (line[0] == 'c' && line[1] == 'a' && line[2] == 't' && line[3] == ' ')
-        {
-            cat(&line[4]);
-            continue;
-        }
-
-        if (line[0] == 't' && line[1] == 'o' && line[2] == 'u' && line[3] == 'c' && line[4] == 'h' && line[5] == ' ')
-        {
-            touch(&line[6]);
-            continue;
-        }
-
-        if (line[0] == 'l' && line[1] == 's')
-        {
-            if (line[2] == ' ')
-                ls(&line[3]);
-            else
-                ls(NULL);
-
-            continue;
-        }
-
-        if (line[0] != '\0')
-            print("Unknown command\n");
-    }
+    printf("comp");
 
     return 0;
 }