Displaying a progress bar is causing an ioctl error when standard out is

From: Philip Soltero <psoltero@cs.unm.edu>

redirected. Disable the progress bar if this error occurs.
---
 utils/guest_creator/main.c |   47 +++++++++++++++++++++++++++-----------------
 1 files changed, 29 insertions(+), 18 deletions(-)

diff --git a/utils/guest_creator/main.c b/utils/guest_creator/main.c
index 15b85ce..ced8dd8 100644
--- a/utils/guest_creator/main.c
+++ b/utils/guest_creator/main.c
@@ -1,6 +1,8 @@
 #include "ezxml.h"
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <getopt.h>
 #include <unistd.h>
 #include <string.h>
@@ -19,6 +21,7 @@ struct file_info {
 
 int num_files = 0;
 struct file_info files[MAX_FILES];
+int silent = 0;
 
 #define STDIO_FD 1
 
@@ -232,63 +235,69 @@ int copy_file(int file_index, FILE * data_file) {
     int prog_len = 0;
     double ratio = 100;
     int num_dots = 256;
+    int progress_bar = 1;
 
     printf("Copying [%d] -- %s \n",
 	   file_index,	   
 	   filename);
 
-
     if (ioctl(STDIO_FD, TIOCGWINSZ, &wsz) == -1) {
-	printf("ioctl error on STDIO\n");
-	return -1;
+        if (errno == ENOTTY) {
+            progress_bar = 0;
+        } else {
+            printf("ioctl error on STDIO\n");
+            return -1;
+        }
     }
 
-
     memset(cons_line, 0, 256);
     snprintf(cons_line, 256, "\r(%s) [", files[file_index].id);
     prog_len = wsz.ws_col - (strlen(cons_line) + 11);
 
-
-
     in_file = fopen(filename, "r");
 
     while (bytes_to_read > 0) {
 	struct winsize tmp_wsz;
 	int tmp_dots = 0;
 
-	if (ioctl(STDIO_FD, TIOCGWINSZ, &tmp_wsz) == -1) {
-	    printf("ioctl error on STDIO\n");
-	    return -1;
-	}
 
-	ratio = (double)bytes_read / (double)(files[file_index].size); 
+    if (progress_bar) {
+        if (ioctl(STDIO_FD, TIOCGWINSZ, &tmp_wsz) == -1) {
+            printf("ioctl error on STDIO\n");
+            return -1;
+        }
+    }
+
+	if (progress_bar) {
+	ratio = (double)bytes_read / (double)(files[file_index].size);
 	tmp_dots = (int)(ratio * (double)prog_len);
 
 	if ((tmp_dots != num_dots) || (tmp_wsz.ws_col != wsz.ws_col)) {
 	    int i = 0;
 	    int num_blanks = 0;
-	    
+
 	    wsz = tmp_wsz;
 	    num_dots = tmp_dots;
-	    
+
 	    num_blanks = prog_len - num_dots;
 
 	    memset(cons_line, 0, 256);
 	    snprintf(cons_line, 256, "\r(%s) [", files[file_index].id);
-	    
+
 	    for (i = 0; i <= num_dots; i++) {
 		strcat(cons_line, "=");
 	    }
-	    
+
 	    for (i = 0; i < num_blanks - 1; i++) {
 		strcat(cons_line, " ");
 	    }
-	    
+
 	    strcat(cons_line, "] ");
 
 	    //	printf("console width = %d\n", wsz.ws_col);
 	    write(STDIO_FD, cons_line, wsz.ws_col);
 	}
+	}
 	
 	
 	
@@ -311,8 +320,10 @@ int copy_file(int file_index, FILE * data_file) {
 	bytes_to_read -= xfer_len;
     }
 
-    strcat(cons_line, "Done\n");
-    write(STDIO_FD, cons_line, wsz.ws_col);
+    if (progress_bar) {
+        strcat(cons_line, "Done\n");
+        write(STDIO_FD, cons_line, wsz.ws_col);
+    }
 
 
     fclose(in_file);