1 files changed, 126 insertions, 0 deletions
diff --git a/pgm3/totalsize.c b/pgm3/totalsize.c
new file mode 100644
index 0000000..c15a72d
--- /dev/null
+++ b/pgm3/totalsize.c
@@ -0,0 +1,126 @@
+#include <errno.h>
+#include <math.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
+#include <time.h>
+#include <unistd.h>
+
+#define FALSE 0
+#define FILE_BUFF 4096
+#define TRUE  1
+
+struct NODE {
+    int inode;
+    long size;
+    struct NODE *next;
+};
+
+int main() {
+    /*
+     * totalsize takes in a list of filenames on its stdin and adds up the
+     * total size of those files (using stat) and prints the results as
+     * either bytes or kilobytes. It checks the UNITS environment variable to
+     * know whether to print in bytes or kilobytes. It checks the TSTALL
+     * environment variable for an integer to use as a delay before checking
+     * for files. It also checks the TMOM environment variable for the
+     * process ID of a parent process to send a SIGUSR1 signal to.
+     *
+     * totalsize builds a linked list out of the entered filenames and then
+     * goes through the unique, regular files and uses stat() to grab
+     * information about those files (inode, size).
+     */
+    char *envar = NULL;
+    char filename[FILE_BUFF];
+    int inList = FALSE;
+    int sigPID;
+    int sleepTime;
+    long long byteSum = 0;
+    struct NODE *currentNode = NULL;
+    struct NODE *head = NULL;
+    struct NODE *newNode = NULL;
+    struct stat statData;
+
+    // Check TSTALL for time delay
+    errno = 0;
+
+    if ((envar = getenv("TSTALL")) != NULL
+            && (sleepTime = strtol(envar, NULL, 10)) > 0
+            && errno == 0) {
+        sleep(sleepTime);
+    }
+
+    // Take in standard input and build linked list.
+    while (scanf(" %s", filename) == 1) {
+
+        if (stat(filename, &statData) == 0 && S_ISREG(statData.st_mode)) {
+            inList = FALSE;
+
+            for (currentNode = head; currentNode != NULL; currentNode = currentNode->next) {
+
+                if (currentNode->inode == statData.st_ino) {
+                    inList = TRUE;
+                }
+
+            }
+
+            if (!inList) {
+                newNode = (struct NODE *) malloc(sizeof(struct NODE));
+                newNode->inode = statData.st_ino;
+                newNode->size = statData.st_size;
+                newNode->next = head;
+                head = newNode;
+            }
+
+        }
+
+        // Check TSTALL for time delay
+        errno = 0;
+
+        if ((envar = getenv("TSTALL")) != NULL
+                && (sleepTime = strtol(envar, NULL, 10)) > 0
+                && errno == 0) {
+            sleep(sleepTime);
+        }
+
+    }
+
+    // Add up the number of bytes and print out the results
+    byteSum = 0;
+
+    for (currentNode = head; currentNode != NULL; currentNode = currentNode->next) {
+        byteSum += currentNode->size;
+    }
+
+    if ((envar = getenv("UNITS")) != NULL
+            && (envar[0] == 'k' || envar[0] == 'K')
+            && envar[1] == '\0') {
+        byteSum /= 1024;
+        printf("%lldkB\n", byteSum);
+    }
+    else {
+        printf("%lld\n", byteSum);
+    }
+
+    // Free list
+    while (currentNode != NULL) {
+        currentNode = head;
+        head = head->next;
+        free(currentNode);
+    }
+
+    errno = 0;
+
+    // Send SIGNUSR1 signal to calling parent
+    if ((envar = getenv("TMOM")) != NULL
+            && (sigPID = strtol(envar, NULL, 10)) > 0
+            && errno == 0) {
+        kill(sigPID, SIGUSR1);
+    }
+
+    exit(0);
+}