Mini shell code

myshell.c

+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h> 
+
+#define MAX 60
+
+
+// Read a line from stdin
+char *readcommand(){
+	
+	char *line = (char*) malloc(sizeof(char) * MAX);
+	printf("$> ");
+	fgets(line, MAX, stdin);
+	
+	size_t ln = strlen(line)-1;
+	if (line[ln] == '\n')
+   	 line[ln] = '\0';
+
+	return line;
+}
+
+// Split the line into tokens 
+char **splitcommand(char *line){
+	
+	char delim[] = " ";
+
+	char *ptr = strtok(line, delim);
+	char **tokens = (char**) malloc(sizeof(char) * MAX);
+	int index =0;
+	while(ptr != NULL)
+	{
+		tokens[index]=ptr;
+		index++;
+	//	printf("'%s'\n", ptr);
+		ptr = strtok(NULL, delim);
+	}
+	return tokens;
+}
+
+// write to file
+void writeBye(char *filename){
+   FILE *fptr;
+
+    // opening file in writing mode
+   fptr = fopen(filename, "w");
+    
+    // exiting program 
+   if (fptr == NULL) {
+      printf("Error!");
+      exit(1);
+    }
+    fprintf(fptr, "%s", "Bye!\n");
+    fclose(fptr);
+}
+
+
+int main(int argc, char** argv)
+{
+
+	if(argc < 2){
+	printf("Please insert exitfile as an argument!\n");
+	return;
+	}	
+	while(1){
+	
+	char *line;
+	char **tokens;
+	
+	line = readcommand();
+	tokens = splitcommand(line);
+	
+	if(strcmp(tokens[0],"exit")==0){
+		
+		writeBye(argv[1]);		
+		exit(0);
+
+	}
+	if(fork()==0){
+		if(execvp(tokens[0], tokens) == -1){
+				perror("The following error occured: ");
+		}
+		exit(1);
+	}else
+	wait(0);	
+}
+return 0;
+}