vmon: save snapshots on SIGUSR1 as well

This adds an externally triggered means of snapshotting, which
is always available, not only with --snapshot.

1 files changed, 19 insertions, 1 deletions

diff --git a/src/vmon.c b/src/vmon.c
index 9a32031..5f865ab 100644
--- a/src/vmon.c
+++ b/src/vmon.c
@@ -63,7 +63,7 @@ typedef struct vmon_t {
 #define WIDTH_MIN	200
 #define HEIGHT_MIN	28
 
-static volatile int got_sigchld;
+static volatile int got_sigchld, got_sigusr1;
 
 /* return if arg == flag or altflag if provided */
 static int is_flag(const char *arg, const char *flag, const char *altflag)
@@ -225,6 +225,12 @@ static void handle_sigchld(int signum)
 }
 
 
+static void handle_sigusr1(int signum)
+{
+	got_sigusr1 = 1;
+}
+
+
 /* parse and apply argv, implementing an strace-like cli, mutates vmon. */
 static int vmon_handle_argv(vmon_t *vmon, int argc, char * const argv[])
 {
@@ -400,6 +406,11 @@ static vmon_t * vmon_startup(int argc, char * const argv[])
 		goto _err_charts;
 	}
 
+	if (signal(SIGUSR1, handle_sigusr1) == SIG_ERR) {
+		VWM_PERROR("unable to set SIGUSR1 handler");
+		goto _err_charts;
+	}
+
 	vmon->chart = vwm_chart_create(vmon->charts, vmon->pid, vmon->width, vmon->height, vmon->name);
 	if (!vmon->chart) {
 		VWM_ERROR("unable to create chart");
@@ -667,6 +678,13 @@ int main(int argc, char * const argv[])
 					vmon->done = 1;
 			}
 		}
+
+		if (got_sigusr1) {
+			if (vmon_snapshot(vmon) < 0)
+				VWM_ERROR("error saving snapshot");
+
+			got_sigusr1 = 0;
+		}
 	}
 
 	vmon_shutdown(vmon);