Print errors to stderr.

Signed-off-by: Drew Fisher <drew.m.fisher@gmail.com>

diff --git a/touchmouse.c b/touchmouse.c
index 47a52539a107725b00fa63af88a14b50900c2861..02baba09522f4b9cb23fd91434a5ad2427c99413 100644 (file)
--- a/touchmouse.c
+++ b/touchmouse.c
@@ -141,7 +141,7 @@ enum {
 int process_nybble(decoder* state, uint8_t nybble) {
        //printf("process_nybble: buf_index = %d\t%01x\n", state->buf_index, nybble);
        if (nybble >= 16) {
-               printf("process_nybble: got nybble >= 16, wtf: %d\n", nybble);
+               fprintf(stderr, "process_nybble: got nybble >= 16, wtf: %d\n", nybble);
                return DECODER_ERROR;
        }
        if (state->next_is_run_encoded) {
@@ -149,6 +149,7 @@ int process_nybble(decoder* state, uint8_t nybble) {
                if (state->buf_index + nybble + 3 > 181) {
                        // Completing this decode would overrun the buffer.  We've been
                        // given invalid data.  Abort.
+                       fprintf(stderr, "process_nybble: run encoded would overflow buffer: got 0xF%x (%d zeros) with only %d bytes to fill in buffer\n", nybble, nybble + 3, 181 - state->buf_index);
                        return DECODER_ERROR;
                }
                int i;
@@ -219,7 +220,7 @@ int enable_mouse_image_mode(hid_device* dev) {
                printf("\n");
        }
        if (transferred != 0x1B) {
-               printf("Failed to read Feature 0x22 correctly; expected 27 bytes, got %d\n", transferred);
+               fprintf(stderr, "Failed to read Feature 0x22 correctly; expected 27 bytes, got %d\n", transferred);
                return -1;
        }
 
@@ -234,7 +235,7 @@ int enable_mouse_image_mode(hid_device* dev) {
                printf("Successfully enabled full touch updates.\n");
                return 0;
        }
-       printf("Failed to enable full touch updates.\n");
+       fprintf(stderr, "Failed to enable full touch updates.\n");
        return -1;
 }
 
@@ -256,17 +257,21 @@ int main(void) {
                cur_dev = cur_dev->next;
        }
        if (!path) {
-               printf("Couldn't find TouchMouse, aborting\n");
+               fprintf(stderr, "Couldn't find TouchMouse, aborting\n");
                return -1;
        }
        dev = hid_open_path(path);
+       if (!dev) {
+               fprintf(stderr, "Failed to open device %s, aborting\n", path);
+               return -1;
+       }
        hid_free_enumeration(devs);
 
        // Enable image updates
        int res = 0;
        res = enable_mouse_image_mode(dev);
        if (res != 0) {
-               printf("Failed to enable full touch updates, aborting\n");
+               fprintf(stderr, "Failed to enable full touch updates, aborting\n");
                return -1;
        }
 
@@ -284,7 +289,7 @@ int main(void) {
        while(!quit) {
                res = hid_read_timeout(dev, data, 255, 100); // 100 msec is hardly noticable, but keeps us from pegging a CPU core
                if (res < 0 ) {
-                       printf("hid_read() failed: %d\n", res);
+                       fprintf(stderr, "hid_read() failed: %d\n", res);
                        return -1;
                } else if (res > 0) {
                        // Dump contents of transfer
@@ -318,7 +323,7 @@ int main(void) {
                                                break;
                                        }
                                        if (res == DECODER_ERROR) {
-                                               printf("Caught error in decoder, aborting!\n");
+                                               fprintf(stderr, "Caught error in decoder, aborting!\n");
                                                goto cleanup;
                                        }
                                        res = process_nybble(state, (r->data[t] & 0xf0) >> 4);
@@ -328,7 +333,7 @@ int main(void) {
                                                break;
                                        }
                                        if (res == DECODER_ERROR) {
-                                               printf("Caught error in decoder, aborting!\n");
+                                               fprintf(stderr, "Caught error in decoder, aborting!\n");
                                                goto cleanup;
                                        }
                                }