From 1bca3de24d6bd15fdecd43a030270d5f512c1496 Mon Sep 17 00:00:00 2001
From: Sagi Dayan <sagidayan@gmail.com>
Date: Wed, 26 Mar 2014 15:52:32 +0200
Subject: [PATCH] SIGINT detection works now. adding some documentatios, still
 need to find memoty leaks

---
 main.c | 109 +++++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 72 insertions(+), 37 deletions(-)

diff --git a/main.c b/main.c
index 473ae75..90da7b7 100644
--- a/main.c
+++ b/main.c
@@ -20,6 +20,8 @@ char** ReadTokens(FILE* stream, int* writeToFile) ;
 void FreeTokens(char** tokens) ;
 void checkIfQuit(char* word);
 int getFileNameIndex(char** args);
+void freeRemainderInArr(char** args, int beforLast);
+
 
 
 int main()
@@ -35,18 +37,20 @@ int main()
 	if(getUserName(user_n) == ERROR)
 		goto quit;
 
+	signal(SIGINT, SIG_IGN); // ignore SIGINT
+
 	while(1)
 	{
-		printf("%d %s@%s$ ",exitCode, user_n, host_n);
-		args = ReadTokens(stdin, &writeToFile);
-		if(args != NULL)
+		printf("%d %s@%s$ ",exitCode, user_n, host_n); // Print Prompt
+		args = ReadTokens(stdin, &writeToFile); // get user command and tokenize it to args, check if there is a redirect to file.
+		if(args != NULL) // if user did enter a command do the following
 		{
-			exitCode = runExec(args, writeToFile);
+			exitCode = runExec(args, writeToFile); // fork and run the process, return child exit code
 			FreeTokens(args); //in case of error while trying to create process - this method will free the memory already
-			if(exitCode == ERROR)
+			if(exitCode == ERROR) // in case we need to exit.
 				goto quit;
 		}
-		writeToFile = false;
+		writeToFile = false; // set the "boolean" back to default
 	}
 
 	quit:
@@ -55,25 +59,35 @@ int main()
 	return 0;
 }
 
-int getHostName(char* host)
-{
-	if(gethostname(host, 10) != 0)
-	{
-		fprintf(stderr, "%s\n", "Error: while getting host name");
-		return -1;
-	}
-	return 0;
-}
+/**
+ * Atemting to get the host name from the system
+ * @param  host  - the string that will hold the host name
+ * @return      0 if all went well, -1 (ERROR) otherwise 
+ */
+ int getHostName(char* host)
+ {
+ 	if(gethostname(host, 10) != 0)
+ 	{
+ 		fprintf(stderr, "%s\n", "Error: while getting host name");
+ 		return ERROR;
+ 	}
+ 	return 0;
+ }
 
-int getUserName(char* name)
-{
-	if(getlogin_r(name, 10) != 0)
-	{
-		fprintf(stderr, "%s\n", "Error: while getting User name");
-		return ERROR;
-	}
-	return 0;
-}
+/**
+ * Atemting to get the user name from the system
+ * @param  host  - the string that will hold the user name
+ * @return      0 if all went well, -1 (ERROR) otherwise 
+ */
+ int getUserName(char* name)
+ {
+ 	if(getlogin_r(name, 10) != 0)
+ 	{
+ 		fprintf(stderr, "%s\n", "Error: while getting User name");
+ 		return ERROR;
+ 	}
+ 	return 0;
+ }
 
 /**
  * This function will atempt to create a new Process.
@@ -100,26 +114,39 @@ int getUserName(char* name)
  	}
 	else if(pid == 0) // child
 	{
+		signal(SIGINT, SIG_DFL); // set the child SIGINT handler to default! -> ^C will kill child but not father.
+		
 		if(writeToFile == true)
 		{
 			int i_lastArg = getFileNameIndex(args);
 			char* fileName = (char *)malloc(strlen(args[i_lastArg])*sizeof(char));
 			strcpy(fileName, args[i_lastArg]);
-			args[i_lastArg - 1] = NULL;
+			freeRemainderInArr(args, i_lastArg);
+			
 			int fd = open(fileName, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
-			dup2(fd, 1);   // make stdout go to file
-			dup2(fd, 2);   // make stderr go to file
-			close(fd);
+			if(fd >= 0)
+			{
+				dup2(fd, 1);   // make stdout go to file
+				close(fd);
+			}
+			else
+			{
+				fprintf(stderr, "%s%s%s\n", "Unable to open file ",fileName," : printing out put to default stdout:");
+			}
 
-	    }
-	    if(execv(path, args) != 0)
-	    {
-	    	fprintf(stderr, "%s%s%s\n", "myTerminal: ", args[0] ,": command not found");
+
+		}
+
+
+		if(execv(path, args) != 0)
+		{
+			fprintf(stderr, "%s%s%s\n", "myTerminal: ", args[0] ,": command not found");
 			exit(1); //child error - chield needs to be closed manually. exit code 225;
 		}
 	}
 	else //pid > 0 father
 		waitpid(pid,&status,0);
+
 	free(path);
 	free(exe);
 	if(status == EXIT_1) //in my computer exit(1) returns 256 - ex demands wanted 255
@@ -176,10 +203,10 @@ int getUserName(char* name)
 		if(i == wordCnt-2) // one before the last argument. to see if to put output into file.
 			if(strcmp(">", returnArr[i]) == 0)
 				*writeToFile = true;
-		tok = strtok(NULL, " \n");
-		i++;
-	}
-	
+			tok = strtok(NULL, " \n");
+			i++;
+		}
+
 	returnArr[wordCnt] = NULL; // the last index will be NULL - so we know where the end is.
 	return returnArr;
 }
@@ -236,4 +263,12 @@ int getFileNameIndex(char** args)
 	while(args[i] != NULL)
 		i++;
 	return i-1;
-}
\ No newline at end of file
+}
+
+void freeRemainderInArr(char** args, int beforLast)
+{
+	free(args[beforLast+1]);
+	args[beforLast] = NULL;
+	free(args[beforLast]);
+	args[beforLast - 1] = NULL;
+}