From 182788482e8bd01c70bbe6af3f7ed79765d4fe53 Mon Sep 17 00:00:00 2001
From: Niklas Halle <niklas@niklashalle.net>
Date: Tue, 19 May 2020 19:58:54 +0200
Subject: exec shit works, kinda

---
 02_exercise/shell.c | 122 ++++++++++++++++++++++++++++++++++------------------
 1 file changed, 80 insertions(+), 42 deletions(-)

diff --git a/02_exercise/shell.c b/02_exercise/shell.c
index 2594d6b..75e77b7 100644
--- a/02_exercise/shell.c
+++ b/02_exercise/shell.c
@@ -11,72 +11,110 @@
 
 #include "array.h"
 #include "errno.h"
-#include "stdbool.h"
+#include <stdbool.h>
 
-void print_prompt(char const *const original_wd, char const *current_wd);
+void print_prompt();
 
-// Returns the return code of the executed programm
-int exec_command(char *command);
+// returns the return code of the executed program
+int exec_command(const char *path, char *const argv[], unsigned timeout);
 
-int main(void) {
-    // the directory is specified without a / at the end
-    char const *const original_wd = get_current_dir_name();
-    char const *current_wd = get_current_dir_name();
+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;
         size_t cap = 0;
         size_t length = 0;
 
-        print_prompt(original_wd, current_wd);
+        print_prompt();
         if ((length = getline(&command, &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;
+            }
+        }
+*/
         if (strstr(command, "cd") != NULL) {
             printf("Changing dirs \n");
             chdir("beispiele");
-            free((void *) current_wd);
-            current_wd = get_current_dir_name();
         } else if (strcmp(command, "exit\n") == 0) {
             exit(0);
         } else {
-            exec_command(command);
+            exec_command(command, (char *const []) {command, NULL}, 0);
         }
         free((void *)command);
     }
-    // Gotta cast to void otherwise we discard qualifiers
-    free((void *)original_wd);
-    free((void *)current_wd);
 }
 
-void print_prompt(char const *const original_wd, char const *const current_wd) {
-    // easiest case first
-    {
-        int result = strcmp(original_wd, current_wd);
-        if (result == 0) {
-            printf(".> ");
-            return;
-        }
-    }
-    printf("%s > ", current_wd);
-    // Now checking for substrings aka are we in a subdir
-    {
-        size_t dirlen = strlen(original_wd);
-        char *const orig_dir_with_slash = malloc(dirlen + 2);
-        if (orig_dir_with_slash == NULL) {
-            fprintf(stderr, "Failed to allocate for prompt");
-            exit(ENOMEM);
-        }
-        memcpy(orig_dir_with_slash, original_wd, dirlen);
-        orig_dir_with_slash[dirlen] = '/';
-        orig_dir_with_slash[dirlen + 1] = '\0';
-        char const *const result = strstr(current_wd, original_wd);
-        if (result != NULL) {
-            printf(".%s > ", current_wd + dirlen);
-            return;
-        }
+void print_prompt() {
+    size_t length  = 1024;
+    char   *buffer = malloc(length * sizeof(char));
+    getcwd(buffer, length);
+    if (buffer == NULL) {
+        printf(".> ");
+    } else {
+        printf("%s > ", buffer);
     }
 }
 
-int exec_command(char *command) { return 0; }
+int exec_command(const char *path, char *const argv[], unsigned timeout) {
+    int  pid;
+    int  pipefd[2];
+    int  status;
+    char buf[512];
+
+    pipe(pipefd);
+    if ((pid = fork()) == 0) {
+        close(pipefd[0]);
+        dup2(pipefd[1], 1); // includes close(1);
+        close(pipefd[1]);
+        execvp(path, argv);
+        fprintf(stderr, "no program\n");
+        exit(-1);
+    }
+
+    if (pid < 0) {
+        fprintf(stderr, "no fork\n");
+        exit(-2);
+    }
+
+    close(pipefd[1]);
+
+    size_t length = 0;
+    if ((length = read(pipefd[0], buf, 512)) <= 0) {
+        fprintf(stderr, "error\n");
+        exit(-3);
+    }
+
+    waitpid(pid, &status, 0);
+
+    close(pipefd[0]);
+
+    buf[length] = '\0';
+
+    printf("%s", buf);
+    return WEXITSTATUS(status);
+}
\ No newline at end of file
-- 
cgit v1.2.3-54-g00ecf