don't continue when malloc bails out

[rigol] / rigol.c

diff --git a/rigol.c b/rigol.c
index e7497ac65444fa4b9c10eaaf99e09ceced8968a8..0e9ff9e9e5bbe226322a220eba4f904344dccff7 100644 (file)
--- a/rigol.c
+++ b/rigol.c
@@ -23,6 +23,8 @@ rmmod uhci_hcd; modprobe uhci_hcd
 #include <readline/readline.h>
 #include <readline/history.h>
 
+#include "png.h"
+
 
 //This routine locates a scope by VID/PID and returns an opened handle to it.
 usb_dev_handle *find_scope() {
@@ -300,13 +302,13 @@ void do_get_buf (struct usb_dev_handle *sc)
 void do_get_screen(struct usb_dev_handle *sc)
 {
        unsigned char screen[320*234];
-       unsigned char screen_conv[320*234*3];
-       unsigned char lut[256][3];
        time_t lt;
        char filename[256];
-       int i;
+       unsigned char *png;
+       int imglen;
+       int ret;
        int l;
-       FILE *fp;
+       int fd;
        pid_t display;
 
        /* Hide "RMT" from screen */
@@ -319,25 +321,26 @@ void do_get_screen(struct usb_dev_handle *sc)
                printf ("hmm. didnt' get %d bytes, but %d\n\n", sizeof(screen), l); 
        }
 
-       for(i = 0; i < 256; i++) {
-               lut[i][0] = ((i >> 6) * 0x55);
-               lut[i][1] = ((((i >> 3) & 7) * 0x49) >> 1);
-               lut[i][2] = (((i & 7) * 0x49) >> 1);
-       }
-
-       for(i = 0; i < sizeof(screen_conv); i += 3) {
-               screen_conv[i] = lut[screen[i/3]][0];
-               screen_conv[i+1] = lut[screen[i/3]][1];
-               screen_conv[i+2] = lut[screen[i/3]][2];
-       }
+       png = lcd2png(screen, &imglen);
 
        lt = time(NULL);
-       strftime(filename, sizeof(filename), "screen_%Y%m%d-%H%M%S.ppm", localtime(&lt));
+       strftime(filename, sizeof(filename), "screen_%Y%m%d-%H%M%S.png", localtime(&lt));
+       fd=open(filename, O_CREAT|O_WRONLY, 0644);
+       if (fd == -1) {
+               perror("open");
+               exit(EXIT_FAILURE);
+       }
 
-       fp = fopen (filename, "w");
-       fprintf(fp, "P6\n320 234\n255\n");
-       fwrite(screen_conv, sizeof(screen_conv), 1, fp);
-       fclose (fp); 
+       while(imglen > 0) {
+               ret = write(fd, png, imglen);
+               if (ret == -1) {
+                       perror("write");
+                       exit(EXIT_FAILURE);
+               }
+               imglen -= ret;
+       }
+       close(fd);
+       free(png);
 
        printf("Waveform saved as %s\n", filename);