final changes

assignment1/demo

+echo hi
+echo hi >> file
+pwd
+echo hi >> file
+pwd
\ No newline at end of file

assignment1/myshell.c

@@ -4,12 +4,24 @@
 #include <string.h>
 #include <unistd.h>
 #include <time.h>
+#include <sys/stat.h>
 #include <sys/wait.h>
 
 #define MAX_INPUT_SIZE 1024
 #define MAX_TOKEN_SIZE 64
 #define MAX_NUM_TOKENS 64
-extern char **environ;
+// extern char **environ;
+
+int fileExists(char *path){
+    return access( path, F_OK ) != -1 ? 1:0;
+}
+
+int folderExists(const char *path)
+{
+    struct stat stats;
+    stat(path, &stats);
+    return S_ISDIR(stats.st_mode)? 1:0;
+}
 
 void funcExit()
 {
@@ -18,9 +30,13 @@ void funcExit()
 
 void funcEnv()
 {
-    int i;
-    for (i = 0; environ[i] != NULL; i++)
-        printf("%s\n", environ[i]);
+    // int i;
+    // for (i = 0; environ[i] != NULL; i++)
+    //     printf("%s\n", environ[i]);
+    setenv("COURSE", "CS-744", 1);
+    setenv("ASSIGNMENT", "ASSIGNMENT_1", 1);
+    printf("COURSE=%s\nASSIGNMENT=%s\nPWD=%s\n",getenv("COURSE"),getenv("ASSIGNMENT"),getenv("PWD"));
+
 }
 
 void funcClear()
@@ -31,7 +47,10 @@ void funcClear()
 void funcDir(char **tokens)
 {
     char a[150] = "ls -la ";
+    if(folderExists(tokens[1]) || fileExists(tokens[1]))
         system(strcat(a, tokens[1]));
+    else
+        printf("ERROR:Directory does not exist\n");
 }
 
 void funcPwd()
@@ -50,7 +69,7 @@ void funcCd(char *fpath)
 
     if (fpath && chdir(fpath) != 0)
     {
-        printf("ERROR: Directory doesn't exist!\n");
+        printf("ERROR:Directory doesn't exist!\n");
         return;
     }
     printf("BEFORE:\nOLDPWD=%s\nPWD=%s\n", getenv("OLDPWD"), getenv("PWD"));
@@ -86,12 +105,20 @@ void ioRedirect(char **tokens, int n)
     case -1:
         break;
     case 0:
-        if (!strcmp(tokens[n - 2], ">>"))
+        if (!strcmp(tokens[n - 2], ">>")){
                 fp = freopen(tokens[n - 1], "a", stdout);
-        else if (!strcmp(tokens[n - 2], ">"))
+        }
+        else if (!strcmp(tokens[n - 2], ">")){
                 fp = freopen(tokens[n - 1], "w", stdout);
-        else
+        }
+        else{
+            if( fileExists (tokens[n-1])) {
                 fp = freopen(tokens[n - 1], "r", stdin);
+            } else {
+                printf("ERROR:File does not exist\n");
+                exit(0);
+            }
+        }
         strcpy(temp, "/bin/");
         strcat(temp, arglist[0]);
         if (execv(temp, arglist) == -1)
@@ -120,7 +147,7 @@ void handler(int sig)
 
     pid_t pid;
     pid = wait(NULL);
-    printf("\nBackground process [%d] finished.\n", pid);
+    printf("\nMyShell:Background process [%d] finished.\n", pid);
     signal(SIGCHLD, NULL);
     getcwd(temp, 150);
     sprintf(buffer, "%s:$ ", temp);
@@ -323,7 +350,7 @@ int main(int argc, char *argv[])
         fp = fopen(argv[1], "r");
         if (fp < 0)
         {
-            printf("File doesn't exists.");
+            printf("ERROR:File doesn't exist");
             return -1;
         }
     }
@@ -336,12 +363,9 @@ int main(int argc, char *argv[])
         bzero(line, sizeof(line));
         if (argc == 2)
         { // batch mode
-            if (fgets(line, sizeof(line), fp) == NULL)
-            { // file reading finished
+            if(fscanf(fp,"%[^\n]\n",line)==EOF)
                 break;
         }
-            line[strlen(line) - 1] = '\0';
-        }
         else
         { // interactive mode
             funcPwd();
@@ -369,7 +393,7 @@ int main(int argc, char *argv[])
             if (!io)
                 io = strcmp(tokens[i], ">>") == 0 || strcmp(tokens[i], ">") == 0 || strcmp(tokens[i], "<") == 0;
         }
-        t1 = clock();
+
         if (parallel)
             exParallel(tokens, i);
         else if (serial)
@@ -380,34 +404,43 @@ int main(int argc, char *argv[])
             ioRedirect(tokens, i);
         else
         {
+            t1 = clock();
             if (!strcmp(tokens[0], "dir") && i == 2)
             {
                 funcDir(tokens);
+                t1 = clock() - t1;
+                printf("%f sec\n", (double)t1 / CLOCKS_PER_SEC);
             }
             else if (!strcmp(tokens[0], "clear"))
             {
                 funcClear();
+                t1 = clock() - t1;
+                printf("%f sec\n", (double)t1 / CLOCKS_PER_SEC);
             }
             else if (!strcmp(tokens[0], "quit"))
             {
                 funcExit();
+                t1 = clock() - t1;
+                printf("%f sec\n", (double)t1 / CLOCKS_PER_SEC);
             }
             else if (!strcmp(tokens[0], "env"))
             {
                 funcEnv();
+                t1 = clock() - t1;
+                printf("%f sec\n", (double)t1 / CLOCKS_PER_SEC);
             }
             else if (!strcmp(tokens[0], "cd"))
             {
                 funcCd(tokens[1]);
+                t1 = clock() - t1;
+                printf("%f sec\n", (double)t1 / CLOCKS_PER_SEC);
             }
             else
             {
                 system(line);
             }
-        }
 
-        t1 = clock() - t1;
-        printf("%f sec\n", (double)t1 / CLOCKS_PER_SEC);
+        }
 
         // Freeing the allocated memory
         for (i = 0; tokens[i] != NULL; i++)