From 5123dd8d66a28a7bf5ca6fb2ed684492edb7e4b1 Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Wed, 2 Apr 2014 14:03:15 +0200 Subject: document MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- src/blueshift_idcrtc.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'src') diff --git a/src/blueshift_idcrtc.c b/src/blueshift_idcrtc.c index 71206f2..978a71d 100644 --- a/src/blueshift_idcrtc.c +++ b/src/blueshift_idcrtc.c @@ -269,29 +269,40 @@ int main(int argc, char** argv) char* atom_name_; int atom_name_len; + /* Acuire the atom name. */ atom_name_cookie = xcb_get_atom_name(connection, *atoms); atom_name_reply = xcb_get_atom_name_reply(connection, atom_name_cookie, &error); if (error) { + /* On error print an error message, */ fprintf(stderr, "RandR atom name query returned %i\n", error->error_code); + /* and release the property list, */ free(prop_reply); + /* the output information resources */ free(out_reply); + /* and the screen information resources. */ free(res_reply); + /* And then close the connection to the display. */ xcb_disconnect(connection); return 1; } + /* Extract the atom name from the data structure that holds it. */ atom_name_ = xcb_get_atom_name_name(atom_name_reply); + /* As well as the length of the name; it is not NUL-termianted.*/ atom_name_len = xcb_get_atom_name_name_length(atom_name_reply); + /* NUL-terminate the atom name. */ atom_name = alloca((atom_name_len + 1) * sizeof(char)); memcpy(atom_name, atom_name_, atom_name_len * sizeof(char)); *(atom_name + atom_name_len) = 0; + /* (It is allocated on the stack, so it should not be free:d.) */ /* Get output identifier */ + /* Look for the the property named EDID. */ if (!strcmp(atom_name, "EDID")) { xcb_randr_get_output_property_cookie_t atom_cookie; @@ -300,6 +311,7 @@ int main(int argc, char** argv) unsigned char* atom_data_; char* atom_data; + /* Acquire the property's value, we know that it is 128 byte long. */ atom_cookie = xcb_randr_get_output_property(connection, outputs[output_i], *atoms, XCB_GET_PROPERTY_TYPE_ANY, 0, 128, 0, 0); @@ -307,28 +319,40 @@ int main(int argc, char** argv) if (error) { + /* On error print an error message, */ fprintf(stderr, "RandR atom data query returned %i\n", error->error_code); + /* and release the property name, */ free(atom_name_reply); + /* release the property list, */ free(prop_reply); + /* the output information resources */ free(out_reply); + /* and the screen information resources. */ free(res_reply); + /* And then close the connection to the display. */ xcb_disconnect(connection); return 1; } + /* Extract the property's value, */ atom_data_ = xcb_randr_get_output_property_data(atom_reply); + /* and its actual length, it is still probably 128 byte, it should be that. */ length = xcb_randr_get_output_property_data_length(atom_reply); + /* Convert to hexadecimal representation. */ atom_data = alloca((2 * length + 1) * sizeof(char)); for (i = 0; i < length; i++) { *(atom_data + i * 2 + 0) = "0123456789abcdef"[(*(atom_data_ + i) >> 4) & 15]; *(atom_data + i * 2 + 1) = "0123456789abcdef"[(*(atom_data_ + i) >> 0) & 15]; } + /* NUL-terminate. */ *(atom_data + 2 * length) = 0; + /* Print the property's name and values. */ printf(" %s: %s\n", atom_name, atom_data); + /* Free the proprty value. */ free(atom_reply); } -- cgit v1.2.3-70-g09d2