A little closer

improbabilitydrive.c

@@ -15,7 +15,7 @@
 typedef struct LNode LNode;
 struct LNode
 {
-    char *fname;
+    char fname[256];
     LNode *next;
 };
 
@@ -54,7 +54,7 @@ int makeFileList(LNode *dirlist)
         {
             // Add to list of files, and increment index
             LNode *newN = malloc(sizeof(LNode));
-            newN->fname = dir->d_name;
+            strcpy(newN->fname, dir->d_name);
             dp->next = malloc(sizeof(LNode)); 
             dp = newN;
             i += 1;
@@ -90,7 +90,7 @@ int getSHFiles(LNode *fileList, int n, LNode *shList)
         if (dot && !strcmp(dot, ".sh"))
         {
             puts("before sp fname assign");
-            sp->fname = fp->fname;
+            strcpy(sp->fname, fp->fname);
             t += 1;
             puts("before sp->next malloc");
             sp->next = malloc(sizeof(LNode));

improbabilitydrivev02.c

@@ -0,0 +1,225 @@
+//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 <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 construct an array of all files in the directory
+// Returns number of items in the array
+int makeFileList(LNode *dirlist)
+{
+    // 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 array indices
+    int i = 0;
+    
+    // Make copy of the pointer to the list for preservation
+    LNode *dp = dirlist;
+
+    // If directory opened successfully:
+    if (d)
+    {
+        // While anything to read remains
+        while ((dir = readdir(d)) != NULL)
+        {
+            // Add to list of files, and increment index
+            LNode *newN = malloc(sizeof(LNode));
+            strcpy(newN->fname, dir->d_name);
+            dp->next = malloc(sizeof(LNode)); 
+            dp = newN;
+            i += 1;
+        }
+        dp->next = NULL;
+        // No need to leave open.
+        closedir(d);
+    }
+    return i;
+}
+
+// Function to take an array of file names and separate out *.sh files
+int getSHFiles(LNode *fileList, int n, LNode *shList)
+{
+    // Declare int to hold total number of hits
+    int t = 0;
+
+    // Copy the pointers to avoid overwrite
+    LNode *fp = fileList;
+    printf("%p\n",(void*)fp);
+    LNode *sp = shList;
+
+    // Loop over every item in the file list
+    int i;
+    for (i = 0; i < n; i++)
+    {
+        if (fp == NULL)
+            continue;
+        printf("%s\n","Before printname");
+        printf("%s\n",fp->fname);
+        puts("before string right char");
+        // Test if it has the .sh extention
+        char *dot = strrchr(fp->fname,'.');
+        puts("after strrchar");
+        if (dot && !strcmp(dot, ".sh"))
+        {
+            puts("before sp fname assign");
+            strcpy(sp->fname, fp->fname);
+            t += 1;
+            puts("before sp->next malloc");
+            sp->next = malloc(sizeof(LNode));
+            puts("after sp->next");
+            sp = sp->next; 
+            puts("after sp");
+        }
+        fp = fp->next;
+    }
+    sp->next = NULL;
+    return t;
+}
+
+// Create a list of command line commands
+char *cmds[12] = {"ls", "grep", "bash", "vi", "ps", "who", "df", "fortune", "history", "date", "top", "cat"};
+
+// Create corresponding command line argument strings
+LNode *shfiles; // Files ending in .sh
+LNode *files; // List of all files in directory
+
+// 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");
+    // Create vars to hold number of files and .sh files
+    int nf = 0;
+    int ns = 0;
+
+    files = malloc(sizeof(LNode));
+    shfiles = malloc(sizeof(LNode));
+
+    puts("intialize variables");
+
+
+    printf("%p\n",(void*)files);
+    // Populate our lists
+    nf = makeFileList(files);
+    puts("after makeFileList");
+    printf("%p\n",(void*)files);
+    ns = getSHFiles(files, nf, shfiles);
+
+    puts("populate directory");
+
+    // Set up a few things for using makeargv() later
+    char delim[] = " \t";
+    char **destargv;
+
+    puts("after argv stuff");
+
+    // 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() % ns;
+            // Execute bash
+            const char *cmd = cmds[rndCmd];
+            const char *argFile;
+            LNode *sp = shfiles;
+            for (int i = 0; i < ns; i++)
+            {
+                if (i == rndSH)
+                    argFile = shfiles->fname;
+                else
+                    sp = sp->next;
+            }
+            execlp(cmds[rndCmd], cmd, argFile, NULL);
+        }
+        else if (rndCmd == 3)
+        {
+            // Pick a random file to open in vi
+            int rndF = rand() % nf;
+            // Execute vi
+            const char *cmd = cmds[rndCmd];
+            const char *argFile;
+            LNode *fp = files;
+            for (int i = 0; i < nf; i++)
+            {
+                if (i == rndF)
+                    argFile = files->fname;
+                else
+                    fp = fp->next;
+            }
+            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;
+}