crec: Add primitive exception handling

Add very primitive signal handling, we will not attempt to drain any
remaining data etc. simply save out what we have to a file.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/crec.c b/crec.c
index 568e4b78528d7a00b1d85a9b8b97d2d667310500..31703c592ab6d34473b488fc94554be3afc56fd1 100644 (file)
--- a/crec.c
+++ b/crec.c
@@ -74,6 +74,7 @@
 #include "tinycompress/tinycompress.h"
 
 static int verbose;
+static int file;
 
 static const unsigned int DEFAULT_CHANNELS = 1;
 static const unsigned int DEFAULT_RATE = 44100;
@@ -183,6 +184,48 @@ static int print_time(struct compress *compress)
        return 0;
 }
 
+static int finish_record()
+{
+       struct wave_header header;
+       int ret;
+       size_t nread, written;
+
+       if (!file)
+               return -ENOENT;
+
+       /* Get amount of data written to file */
+       ret = lseek(file, 0, SEEK_END);
+       if (ret < 0)
+               return -errno;
+
+       written = ret;
+       if (written < sizeof(header))
+               return -ENOENT;
+       written -= sizeof(header);
+
+       /* Sync file header from file */
+       ret = lseek(file, 0, SEEK_SET);
+       if (ret < 0)
+               return -errno;
+
+       nread = read(file, &header, sizeof(header));
+       if (nread != sizeof(header))
+               return -errno;
+
+       /* Update file header */
+       ret = lseek(file, 0, SEEK_SET);
+       if (ret < 0)
+               return -errno;
+
+       size_wave_header(&header, written);
+
+       written = write(file, &header, sizeof(header));
+       if (written != sizeof(header))
+               return -errno;
+
+       return 0;
+}
+
 void capture_samples(char *name, unsigned int card, unsigned int device,
                     unsigned long buffer_size, unsigned int frag,
                     unsigned int length, unsigned int rate,
@@ -192,7 +235,6 @@ void capture_samples(char *name, unsigned int card, unsigned int device,
        struct snd_codec codec;
        struct compress *compress;
        struct wave_header header;
-       int file;
        char *buffer;
        size_t written;
        int read, ret;
@@ -214,7 +256,7 @@ void capture_samples(char *name, unsigned int card, unsigned int device,
        if (verbose)
                printf("%s: entry, reading %u bytes\n", __func__, length);
 
-       file = open(name, O_WRONLY | O_CREAT);
+       file = open(name, O_RDWR | O_CREAT);
        if (file == -1) {
                fprintf(stderr, "Unable to open file '%s'\n", name);
                exit(EXIT_FAILURE);
@@ -311,17 +353,9 @@ void capture_samples(char *name, unsigned int card, unsigned int device,
                fprintf(stderr, "ERR: %s\n", compress_get_error(compress));
        }
 
-       /* Update file header now we know file size */
-       size_wave_header(&header, total_read);
-       ret = lseek(file, 0, SEEK_SET);
+       ret = finish_record();
        if (ret < 0) {
-               fprintf(stderr, "Error seeking: %s\n", strerror(errno));
-               goto buf_exit;
-       }
-       written = write(file, &header, sizeof(header));
-       if (written != sizeof(header)) {
-               fprintf(stderr, "Error updating output file header: %s\n",
-                       strerror(errno));
+               fprintf(stderr, "Failed to finish header: %s\n", strerror(ret));
                goto buf_exit;
        }
 
@@ -330,6 +364,7 @@ void capture_samples(char *name, unsigned int card, unsigned int device,
 
        free(buffer);
        close(file);
+       file = 0;
 
        compress_close(compress);
 
@@ -347,6 +382,16 @@ file_exit:
        exit(EXIT_FAILURE);
 }
 
+static void sig_handler(int signum __attribute__ ((unused)))
+{
+       finish_record();
+
+       if (file)
+               close(file);
+
+       _exit(EXIT_FAILURE);
+}
+
 int main(int argc, char **argv)
 {
        char *file;
@@ -356,6 +401,11 @@ int main(int argc, char **argv)
        unsigned int rate = DEFAULT_RATE, channels = DEFAULT_CHANNELS;
        unsigned int format = DEFAULT_FORMAT;
 
+       if (signal(SIGINT, sig_handler) == SIG_ERR) {
+               fprintf(stderr, "Error registering signal handler\n");
+               exit(EXIT_FAILURE);
+       }
+
        if (argc < 2)
                usage();