From ddbb47ed661614d768e8ebd3b0a5084ee82b0beb Mon Sep 17 00:00:00 2001
From: Niklas Halle <niklas@niklashalle.net>
Date: Thu, 21 May 2020 10:25:23 +0200
Subject: ?????

---
 02_exercise/shell.c | 103 +++++++++++++++++++++++++++++++++-------------------
 1 file changed, 66 insertions(+), 37 deletions(-)

diff --git a/02_exercise/shell.c b/02_exercise/shell.c
index 75e77b7..84f8aff 100644
--- a/02_exercise/shell.c
+++ b/02_exercise/shell.c
@@ -2,71 +2,100 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include <fcntl.h>
-#include <signal.h>
-#include <sys/stat.h>
-#include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
 #include "array.h"
-#include "errno.h"
 #include <stdbool.h>
 
 void print_prompt();
 
+int parse_line(char const *line, char **exe, char ***parts, size_t *part_count);
+
 // returns the return code of the executed program
 int exec_command(const char *path, char *const argv[], unsigned timeout);
 
 int main(int argc, char* argv[]) {
-
-    char *argument;
-    char **arguments;
-    if (arrayInit(argument) != 0 || arrayInit(arguments) != 0) {
-        fprintf(stderr, "Failed to prepare new argument array");
-        exit(-1);
-    }
-
     while (true) {
-        char *command = NULL;
+        char *line = NULL;
         size_t cap = 0;
         size_t length = 0;
 
         print_prompt();
-        if ((length = getline(&command, &cap, stdin)) < 0) {
+        if ((length = getline(&line, &cap, stdin)) < 0) {
             fprintf(stderr, "Failed to read from STDIN");
             exit(-1);
         }
 
-        command[length - 1] = '\0'; // cut the line feed
-/*
-        char c;
-        int i = 0;
-        while (true) {
-            c = command[i++];
-            if (c == ' ') {
-                arrayPush(argument) = '\0';
-                arrayPush(arguments) = argument;
-                printf("+ %s\n", argument);
-                arrayRelease(argument);
-                arrayInit(argument);
-            } else if (c == '\0') {
-
-            } else {
-                arrayPush(argument) = c;
-            }
+        line[length - 1] = '\0'; // cut the line feed
+
+        char *exe = NULL;
+        char **arguments = NULL;
+        size_t argument_count;
+        parse_line(line, &exe, &arguments, &argument_count);
+
+        for (size_t h = 0; h < argument_count; ++h) {
+            char *part;
+            part = arrayPop(arguments);
+            if (part == NULL)
+                continue;
+            printf("%s\n", part);
         }
-*/
-        if (strstr(command, "cd") != NULL) {
+
+        exit(0);
+
+        if (strcmp(exe, "cd") == 0) {
             printf("Changing dirs \n");
             chdir("beispiele");
-        } else if (strcmp(command, "exit\n") == 0) {
+        } else if (strcmp(exe, "exit") == 0) {
             exit(0);
         } else {
-            exec_command(command, (char *const []) {command, NULL}, 0);
+            exec_command(exe, (char *const []) {exe, NULL}, 0);
+        }
+        free((void *)line);
+        // no need to free exe, since it is part of arguments any way
+        arrayRelease(arguments);
+    }
+}
+
+int parse_line(char const *line, char **exe, char ***parts, size_t *part_count) {
+    char *part;
+    char **local_parts;
+
+    if (arrayInit(part) != 0 || arrayInit(local_parts) != 0) {
+        fprintf(stderr, "Failed to prepare new part array");
+        exit(-1);
+    }
+
+    bool found_exe = false;
+    char c;
+    int i = 0;
+    while (true) {
+        c = line[i++];
+        if (c == ' ' || c == '\0') {
+            arrayPush(part) = '\0';
+            arrayPush(local_parts) = part;
+            if (!found_exe) {
+                // the first is the executable
+                *exe = malloc(arrayLen(part) * sizeof(char));
+                strcpy(*exe, part);
+                found_exe = true;
+            }
+            arrayRelease(part); // TODO: am i supposed/allowed to free it here?
+            arrayInit(part);
+            if (c == '\0') {
+                arrayPush(local_parts) = NULL;
+                break;
+            }
+        } else {
+            arrayPush(part) = c;
         }
-        free((void *)command);
     }
+
+    *part_count = arrayLen(local_parts);
+    *parts = local_parts;
+
+    return 0;
 }
 
 void print_prompt() {
-- 
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