[systemd-devel] [PATCH 2/2] Add a 'b' option to cgtop, equivalent to the same option in top.

[david at davidstrauss.net]

From: David Strauss <david at davidstrauss.net>

---
 src/cgtop/cgtop.c | 30 +++++++++++++++++++++++-------
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/src/cgtop/cgtop.c b/src/cgtop/cgtop.c
index 70570a8..b4454c54 100644
--- a/src/cgtop/cgtop.c
+++ b/src/cgtop/cgtop.c
@@ -66,6 +66,8 @@ static enum {
         ORDER_IO
 } arg_order = ORDER_CPU;
 
+bool arg_batch = false;
+
 static void group_free(Group *g) {
         assert(g);
 
@@ -507,6 +509,7 @@ static void help(void) {
                "  -i                  Order by IO load\n"
                "  -d --delay=DELAY    Specify delay\n"
                "  -n --iterations=N   Run for N iterations before exiting\n"
+               "  -b --batch          Run in batch mode, accepting no input\n"
                "     --depth=DEPTH    Maximum traversal depth (default: 2)\n",
                program_invocation_short_name);
 }
@@ -521,6 +524,7 @@ static int parse_argv(int argc, char *argv[]) {
                 { "help",       no_argument,       NULL, 'h'       },
                 { "delay",      required_argument, NULL, 'd'       },
                 { "iterations", required_argument, NULL, 'n'       },
+                { "batch",      no_argument,       NULL, 'b'       },
                 { "depth",      required_argument, NULL, ARG_DEPTH },
                 { NULL,         0,                 NULL, 0         }
         };
@@ -531,7 +535,7 @@ static int parse_argv(int argc, char *argv[]) {
         assert(argc >= 1);
         assert(argv);
 
-        while ((c = getopt_long(argc, argv, "hptcmin:d:", options, NULL)) >= 0) {
+        while ((c = getopt_long(argc, argv, "hptcmin:bd:", options, NULL)) >= 0) {
 
                 switch (c) {
 
@@ -566,6 +570,10 @@ static int parse_argv(int argc, char *argv[]) {
 
                         break;
 
+                case 'b':
+                        arg_batch = true;
+                        break;
+
                 case 'p':
                         arg_order = ORDER_PATH;
                         break;
@@ -656,17 +664,25 @@ int main(int argc, char *argv[]) {
                 if (arg_iterations && iteration >= arg_iterations)
                         break;
 
-                r = read_one_char(stdin, &key, last_refresh + arg_delay - t, NULL);
-                if (r == -ETIMEDOUT)
-                        continue;
-                if (r < 0) {
-                        log_error("Couldn't read key: %s", strerror(-r));
-                        goto finish;
+                if (!arg_batch) {
+                        r = read_one_char(stdin, &key, last_refresh + arg_delay - t, NULL);
+                        if (r == -ETIMEDOUT)
+                                continue;
+                        if (r < 0) {
+                                log_error("Couldn't read key: %s", strerror(-r));
+                                goto finish;
+                        }
+                }
+                else {
+                        usleep(last_refresh + arg_delay - t);
                 }
 
                 fputs("\r \r", stdout);
                 fflush(stdout);
 
+                if (arg_batch)
+                        continue;
+
                 switch (key) {
 
                 case ' ':
-- 
1.7.11.2