move key event logic to monitor.c

src/app/fdctl/monitor/monitor.c

@@ -7,6 +7,8 @@
 #include <signal.h>
 #include <sys/syscall.h>
 #include <linux/capability.h>
+#include <termios.h>
+#include <fcntl.h>
 
 void
 monitor_cmd_args( int *    pargc,
@@ -293,9 +295,20 @@ run_monitor( config_t * const config,
     if( FD_UNLIKELY( (ulong)n>=buf_sz ) ) FD_LOG_ERR(( "snprintf truncated" )); \
     buf += n; buf_sz -= (ulong)n;                                               \
   } while(0)
-#define TAB 9
   ulong line_count = 0;
   int monitor_pane = 0;
+  /* Disables character echo and canonical mode since we want the input to be processes immediately.*/
+  struct termios terminal_config;
+  if( FD_UNLIKELY( 0!=tcgetattr(STDIN_FILENO, &terminal_config) ) ) FD_LOG_ERR(( "tcgetattr failed" ));
+
+  terminal_config.c_lflag &= (tcflag_t)~(ICANON | ECHO);
+  if( FD_UNLIKELY( 0!=tcsetattr(STDIN_FILENO, TCSANOW, &terminal_config) ) ) FD_LOG_ERR(( "tcsetattr failed" ));
+
+  /* Terminal also set to non blocking in case the user doesn't send any input. */
+  int terminal_flag = fcntl(STDIN_FILENO, F_GETFL, 0);
+  if( FD_UNLIKELY( -1==terminal_flag ) ) FD_LOG_ERR(( "fcntl get flag failed" ));
+  if( FD_UNLIKELY( -1==fcntl(STDIN_FILENO, F_SETFL, terminal_flag | O_NONBLOCK) ) ) FD_LOG_ERR(( "fcntl set flag failed" )); 
+
   for(;;) {
     /* Wait a somewhat randomized amount and then make a diagnostic
        snapshot */
@@ -311,6 +324,7 @@ run_monitor( config_t * const config,
     char * buf = buffer;
     ulong buf_sz = FD_MONITOR_TEXT_BUF_SZ;
 
+
     /* move to beginning of line, n lines ago */
     PRINT( "\033[2J\033[%luF", line_count );
 
@@ -325,7 +339,7 @@ run_monitor( config_t * const config,
 
     char * mon_start = buf;
     if( FD_UNLIKELY( drain_output_fd >= 0 ) ) PRINT( TEXT_NEWLINE );
-    if( FD_UNLIKELY(fd_getch() == TAB) ) monitor_pane = !monitor_pane;
+    if( FD_UNLIKELY(getchar() == '\t') ) monitor_pane = !monitor_pane;
 
     long dt = now-then;