fbsplash: more compact support for named pipes + EOF scenario

function                                             old     new   delta
fbsplash_main                                       1121    1043     -78

diff --git a/miscutils/fbsplash.c b/miscutils/fbsplash.c
index e8bdb405d4e2d63a7726c8dee5803cde62fc58d5..a288b3ca51dd2a690d92b50968e210ff2851c394 100644 (file)
--- a/miscutils/fbsplash.c
+++ b/miscutils/fbsplash.c
@@ -360,6 +360,8 @@ int fbsplash_main(int argc ATTRIBUTE_UNUSED, char **argv)
 {
        const char *fb_device, *cfg_filename, *fifo_filename;
        FILE *fp = fp; // for compiler
+       char *num_buf;
+       unsigned num;
        bool bCursorOff;
 
        INIT_G();
@@ -392,49 +394,7 @@ int fbsplash_main(int argc ATTRIBUTE_UNUSED, char **argv)
                return EXIT_SUCCESS;
 
        fp = xfopen_stdin(fifo_filename);
-
-       while (1) {
-               struct stat statbuf;
-               unsigned num;
-               char *num_buf;
-
-               fb_drawprogressbar(0);
-               // Block on read, waiting for some input.
-               // Use of <stdio.h> style I/O allows to correctly
-               // handle a case when we have many buffered lines
-               // already in the pipe
-               while ((num_buf = xmalloc_fgetline(fp)) != NULL) {
-                       if (strncmp(num_buf, "exit", 4) == 0) {
-                               DEBUG_MESSAGE("exit");
- exit_cmd:
-                               if (bCursorOff) {
-                                       // restore cursor
-                                       full_write(STDOUT_FILENO, "\x1b" "[?25h", 6);
-                               }
-                               return EXIT_SUCCESS;
-                       }
-                       num = atoi(num_buf);
-                       if (isdigit(num_buf[0]) && (num <= 100)) {
-#if DEBUG
-                               char strVal[10];
-                               sprintf(strVal, "%d", num);
-                               DEBUG_MESSAGE(strVal);
-#endif
-                               fb_drawprogressbar(num);
-                       }
-                       free(num_buf);
-               }
-               // We got EOF/error on fp
-               if (ferror(fp))
-                       goto exit_cmd;
-               fclose(fp);
-               if (LONE_DASH(fifo_filename)
-                || stat(fifo_filename, &statbuf) != 0
-                || !S_ISFIFO(statbuf.st_mode)
-               ) {
-                       goto exit_cmd;
-               }
-               // It's really a named pipe!
+       if (fp != stdin) {
                // For named pipes, we want to support this:
                //  mkfifo cmd_pipe
                //  fbsplash -f cmd_pipe .... &
@@ -442,10 +402,37 @@ int fbsplash_main(int argc ATTRIBUTE_UNUSED, char **argv)
                //  echo 33 >cmd_pipe
                //  ...
                //  echo 66 >cmd_pipe
-               // This means that on EOF, we need to close/open cmd_pipe
-               // (just reading again works too, but it hogs CPU)
-               fp = xfopen_stdin(fifo_filename); // blocks on open
-       } // end of while (1)
+               // This means that we don't want fbsplash to get EOF
+               // when last writer closes input end.
+               // The simplest way is to open fifo for writing too
+               // and become an additional writer :)
+               open(fifo_filename, O_WRONLY); // errors are ignored
+       }
+
+       fb_drawprogressbar(0);
+       // Block on read, waiting for some input.
+       // Use of <stdio.h> style I/O allows to correctly
+       // handle a case when we have many buffered lines
+       // already in the pipe
+       while ((num_buf = xmalloc_fgetline(fp)) != NULL) {
+               if (strncmp(num_buf, "exit", 4) == 0) {
+                       DEBUG_MESSAGE("exit");
+                       break;
+               }
+               num = atoi(num_buf);
+               if (isdigit(num_buf[0]) && (num <= 100)) {
+#if DEBUG
+                       char strVal[10];
+                       sprintf(strVal, "%d", num);
+                       DEBUG_MESSAGE(strVal);
+#endif
+                       fb_drawprogressbar(num);
+               }
+               free(num_buf);
+       }
+
+       if (bCursorOff) // restore cursor
+               full_write(STDOUT_FILENO, "\x1b" "[?25h", 6);
 
        return EXIT_SUCCESS;
 }