Finally working! Still some bugs...

cat, grep, bash, and history all fail.

improbabilitydrivev2.c

@@ -0,0 +1,216 @@
+//CS 350 - Processes Group - "CTRL+ALT+BELIEVE"
+// improbabilitydrive.c - The Improbability Drive
+// This program behaves in a very improbable way.
+
+#include <errno.h>
+#include <stdio.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+// Create a linked list struct
+typedef struct LNode LNode;
+struct LNode
+{
+    char fname[256];
+    LNode *next;
+};
+
+// Define a function to restart wait() whenever interrupted
+pid_t r_wait(int *stat_loc)
+{
+    int retval;
+
+    // Loop and call wait() whenever an interrupt error occurs
+    while (((retval = wait(stat_loc)) == -1) && (errno == EINTR)) ;
+    return retval;
+}
+
+// Function to get the total number of files in the directory
+int getFCount()
+{
+	// Special thanks to stackoverflow.com for info on how to get file names
+    // Create a new directory object (using dirent.h)
+    DIR *d;
+    // Make a dirent struct
+    struct dirent *dir;
+    // Try opening the current directory
+    d = opendir(".");
+    // Create an index variable for incrementing total number of files
+    int total = 0;
+    
+    // If directory opened successfully:
+    if (d)
+    {
+        // While anything to read remains
+        while ((dir = readdir(d)) != NULL)
+        {
+            // Increment file total
+            total += 1;
+        }
+        
+		// No need to leave open.
+        closedir(d);
+    }
+    return total;
+}
+
+// Function to get the nth filename in a directory
+char* getFileName(int n)
+{
+	// Create a new directory object (using dirent.h)
+    DIR *d;
+    // Make a dirent struct
+    struct dirent *dir;
+    // Try opening the current directory
+    d = opendir(".");
+	
+	// Create an indexing variable
+	int i = 0;
+	
+	// If directory opened successfully:
+    if (d)
+    {
+        // While anything to read remains
+        while ((dir = readdir(d)) != NULL)
+        {
+            // Check if this is the nth file
+			if (i == n)
+			{
+				// Return the current file name
+				char* fname = malloc(sizeof(char)*strlen(dir->d_name));
+				strcpy(fname, dir->d_name);
+				return fname;
+			}
+        }
+        
+		// No need to leave open.
+        closedir(d);
+    }
+	
+	// If code sees this point, error... Return NULL
+	return NULL;
+}
+
+// Function to verify if given file is an .sh file 
+// 1 = true, 0 = false
+int isSHFile(char* fname)
+{
+	// Test if it has the .sh extention
+	char *dot = strrchr(fname,'.');
+	if (dot && !strcmp(dot, ".sh"))
+	    return 1;
+	else
+	    return 0;
+}
+
+// Create a list of command line commands
+char *cmds[12] = {"ls", "grep", "bash", "vi", "ps", "who", "df", "fortune", "history", "date", "top", "cat"};
+
+// Random words to grep
+char *randwords[6] = {"if", "while", "time", "char", "print", "name"};
+int nw = 6; // Number of words in array
+
+// Main function
+int main(void)
+{
+    puts("beginning of main");
+	
+	// Seed random number generator
+	time_t t;
+	srand((unsigned) time(&t));
+	
+    // Create vars to hold number of files and .sh files
+    int nf = 0;
+    int ns = 0;
+
+    // Get number of files
+	int nf = 0;
+	nf = getFCount();
+	
+    // Create a pid_t to store the pid of the child process we are making
+    pid_t childpid;
+    
+    // Make a child process
+    childpid = fork();
+
+    // Check that it was successful
+    if (childpid == -1)
+    {
+        perror("Failed to fork");
+    }
+
+    // If this is the child:
+    if (childpid == 0)
+    {
+        // Generate a random number to pick a command
+        int rndCmd = rand() % 12;
+
+        // Check which command it is to see if an argument is needed
+        // 1 is grep, 2 is bash, 3 is vi
+        if (rndCmd == 1)
+        {
+            // Pick a random word to grep for
+            int rndW = rand() % nw;
+            // Execute bash 
+            const char *cmd = cmds[rndCmd];
+            const char *argFile = randwords[rndW];
+            execlp(cmds[rndCmd], cmd, argFile, NULL);
+        }
+        else if (rndCmd == 2)
+        {
+            // Pick a random .sh file to run with bash
+            int rndSH = rand() % nf;
+			
+			// Check if not a SH file, restart search if not
+			while ((char* fname = getFileName(rndSH)))
+			{
+				if (!isSHFile(fname))
+				{
+			        rndSH += 1;
+				    if (rndSH > nf)
+				        rndSH = 0;
+				}
+				else
+				{
+					// Execute bash
+					const char *cmd = cmds[rndCmd];
+					const char *argFile = fname;
+					execlp(cmds[rndCmd], cmd, argFile, NULL);
+					break;
+				}
+			}
+			
+            
+        }
+        else if (rndCmd == 3)
+        {
+            // Pick a random file to open in vi
+            int rndF = rand() % nf;
+			
+			// Get file name
+			char* fname = getFileName(rndF);
+			
+            // Execute vi
+            const char *cmd = cmds[rndCmd];
+            const char *argFile = fname;
+            execlp(cmds[rndCmd], cmd, argFile, NULL);
+        }
+        else
+        {
+            // Just run the command
+            const char *cmd = cmds[rndCmd];
+            execlp(cmds[rndCmd], cmd, NULL);
+        }
+    }
+    if (childpid != r_wait(NULL))
+    {
+        perror("Parent failed to wait");
+        return 1;
+    }
+    return 0;
+}