Fix option handling

1 files changed, 8 insertions, 2 deletions

diff --git a/capture.c b/capture.c
index 457e282..9cc43d5 100644
--- a/capture.c
+++ b/capture.c
@@ -613,12 +613,13 @@ usage                           (FILE *                 fp,
                  "-r | --read          Use read() calls\n"
                  "-u | --userp         Use application allocated buffers\n"
                  "-n | --numframes     Number of frames to acquire (default=1)\n"
-                 "-f | --framerate     Frame rate at which to acquire (default: use driver's default)\n"
+                 "-f | --framerate     Frame rate at which to acquire (default: unspecified)\n"
+                 "-o | --outfile       File in which to dump frames as cat'd PGM\n"
                  "",
 		 argv[0]);
 }
 
-static const char short_options [] = "d:hmrunfo";
+static const char short_options [] = "d:hmrun:f:o:";
 
 static const struct option
 long_options [] = {
@@ -686,6 +687,11 @@ main                            (int                    argc,
 
                 case 'o':
                         output_file = fopen(optarg, "wb");
+                        if (!output_file){
+                                fprintf (stderr, "Cannot open '%s': %d, %s\n",
+                                        optarg, errno, strerror (errno));
+                                exit (EXIT_FAILURE);
+                        }
 			break;
 
                 default: