almost final

assignment1/part1.c → assignment1/myshell.c

@@ -60,7 +60,6 @@ void funcCd(char *fpath){
     free(temp);
 }
 
-
 void ioRedirect(char **tokens,int n){
     FILE *fp;
     char **arglist = (char **)malloc(MAX_NUM_TOKENS * sizeof(char *));
@@ -69,29 +68,29 @@ void ioRedirect(char **tokens,int n){
     for(int i=0;strcmp(tokens[i],">>") && strcmp(tokens[i],">") && strcmp(tokens[i],"<");i++){
             arglist[j] = (char*)malloc(MAX_TOKEN_SIZE*sizeof(char));
             strcpy(arglist[j++],tokens[i]);
-        }
-        arglist[j]=NULL;
-        char *temp = (char *)malloc(sizeof(char)*150);
+    }
+    arglist[j]=NULL;
+    char *temp = (char *)malloc(sizeof(char)*150);
 
-        switch (fork()) {
-            case -1:
-                break;
-            case 0: 
-                if(!strcmp(tokens[n-2],">>"))
-                    fp = freopen(tokens[n-1],"a",stdout);
-                else if(!strcmp(tokens[n-2],">"))
-                    fp = freopen(tokens[n-1],"w",stdout);
-                else
-                    fp = freopen(tokens[n-1],"r",stdin);
-                strcpy(temp,"/bin/");
+    switch (fork()) {
+        case -1:
+            break;
+        case 0: 
+            if(!strcmp(tokens[n-2],">>"))
+                fp = freopen(tokens[n-1],"a",stdout);
+            else if(!strcmp(tokens[n-2],">"))
+                fp = freopen(tokens[n-1],"w",stdout);
+            else
+                fp = freopen(tokens[n-1],"r",stdin);
+            strcpy(temp,"/bin/");
+            strcat(temp,arglist[0]);
+            if(execv(temp,arglist)==-1){
+                strcpy(temp,"/usr/bin/");
                 strcat(temp,arglist[0]);
-                if(execv(temp,arglist)==-1){
-                    strcpy(temp,"/usr/bin/");
-                    strcat(temp,arglist[0]);
-                    execv(temp,arglist);
-                }
-                free(temp);
-        }
+                execv(temp,arglist);
+            }
+            free(temp);
+    }
     wait(NULL);
 
     for(int i=0;arglist[i]!=NULL;i++)
@@ -100,9 +99,26 @@ void ioRedirect(char **tokens,int n){
     free(arglist);
 }
 
+// http://www.linuxquestions.org/questions/programming-9/how-a-father-process-know-which-child-process-send-the-signal-sigchld-266290/
+
+void handler(int sig){
+    char *buffer = (char *)malloc(sizeof(char)*100);
+    char *temp = (char *)malloc(sizeof(char)*150);
+
+    pid_t pid;
+    pid = wait(NULL);
+    printf("\nBackground process [%d] finished.\n", pid);
+    signal(SIGCHLD, NULL);
+    getcwd(temp,150);
+    sprintf(buffer,"%s:$ ",temp);
+    write(1,buffer,50);
+    free(temp);
+    free(buffer);
+}
+
 void exBackground(char **tokens,int n){
     char **arglist = (char **)malloc(MAX_NUM_TOKENS * sizeof(char *));
-    int j=0,forkcalls=0;
+    int j=0;
 
     for(int i=0;i<n;i++){
         while(tokens[i]!=NULL && strcmp(tokens[i],"&")!=0 ){
@@ -110,8 +126,8 @@ void exBackground(char **tokens,int n){
             strcpy(arglist[j++],tokens[i++]);
         }
         arglist[j]=NULL;
-        forkcalls++;
         char *temp = (char *)malloc(sizeof(char)*150);
+        signal(SIGCHLD, handler);
 
         switch (fork()) {
             case -1:
@@ -283,19 +299,16 @@ int main(int argc, char* argv[]) {
 			line[strlen(line) - 1] = '\0';
 		} else { // interactive mode
             funcPwd();
-            // waitpid(-1,NULL,WNOHANG);
 			scanf("%[^\n]", line);
 			getchar();
 		}
         if(!strlen(line))
             continue;
-		// printf("Command entered: %s\n", line);
 		/* END: TAKING INPUT */
 
 		line[strlen(line)] = '\n'; //terminate with new line
 		tokens = tokenize(line);
    
-       //do whatever you want with the commands, here we just print them
 		for(i=0;tokens[i]!=NULL;i++){
             if(!parallel)
                 parallel=strcmp(tokens[i],"&&&")==0;
@@ -309,7 +322,6 @@ int main(int argc, char* argv[]) {
             if(!io)
                 io=strcmp(tokens[i],">>")==0 || strcmp(tokens[i],">")==0 || strcmp(tokens[i],"<")==0;
 
-			// printf("found token %s\n", tokens[i]);
 		}
         t1 = clock(); 
         if(parallel)
@@ -321,7 +333,7 @@ int main(int argc, char* argv[]) {
         else if(io)
             ioRedirect(tokens,i);
         else {
-            if(!strcmp(tokens[0],"dir")){
+            if(!strcmp(tokens[0],"dir") && i==2){
                 funcDir(tokens);
             }
             else if(!strcmp(tokens[0],"clear")){