[systemd-devel] [PATCH 1/2] Add an 'n' option to cgtop (equivalent to top).

[david at davidstrauss.net]

From: David Strauss <david at davidstrauss.net>

---
 src/cgtop/cgtop.c | 25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/src/cgtop/cgtop.c b/src/cgtop/cgtop.c
index c3824c7..70570a8 100644
--- a/src/cgtop/cgtop.c
+++ b/src/cgtop/cgtop.c
@@ -55,6 +55,7 @@ typedef struct Group {
 } Group;
 
 static unsigned arg_depth = 3;
+static unsigned arg_iterations = 0;
 static usec_t arg_delay = 1*USEC_PER_SEC;
 
 static enum {
@@ -505,6 +506,7 @@ static void help(void) {
                "  -m                  Order by memory load\n"
                "  -i                  Order by IO load\n"
                "  -d --delay=DELAY    Specify delay\n"
+               "  -n --iterations=N   Run for N iterations before exiting\n"
                "     --depth=DEPTH    Maximum traversal depth (default: 2)\n",
                program_invocation_short_name);
 }
@@ -516,10 +518,11 @@ static int parse_argv(int argc, char *argv[]) {
         };
 
         static const struct option options[] = {
-                { "help",  no_argument,       NULL, 'h'       },
-                { "delay", required_argument, NULL, 'd'       },
-                { "depth", required_argument, NULL, ARG_DEPTH },
-                { NULL,    0,                 NULL, 0         }
+                { "help",       no_argument,       NULL, 'h'       },
+                { "delay",      required_argument, NULL, 'd'       },
+                { "iterations", required_argument, NULL, 'n'       },
+                { "depth",      required_argument, NULL, ARG_DEPTH },
+                { NULL,         0,                 NULL, 0         }
         };
 
         int c;
@@ -528,7 +531,7 @@ static int parse_argv(int argc, char *argv[]) {
         assert(argc >= 1);
         assert(argv);
 
-        while ((c = getopt_long(argc, argv, "hptcmid:", options, NULL)) >= 0) {
+        while ((c = getopt_long(argc, argv, "hptcmin:d:", options, NULL)) >= 0) {
 
                 switch (c) {
 
@@ -554,6 +557,15 @@ static int parse_argv(int argc, char *argv[]) {
 
                         break;
 
+                case 'n':
+                        r = safe_atou(optarg, &arg_iterations);
+                        if (r < 0) {
+                                log_error("Failed to parse iterations parameter.");
+                                return -EINVAL;
+                        }
+
+                        break;
+
                 case 'p':
                         arg_order = ORDER_PATH;
                         break;
@@ -641,6 +653,9 @@ int main(int argc, char *argv[]) {
                 if (r < 0)
                         goto finish;
 
+                if (arg_iterations && iteration >= arg_iterations)
+                        break;
+
                 r = read_one_char(stdin, &key, last_refresh + arg_delay - t, NULL);
                 if (r == -ETIMEDOUT)
                         continue;
-- 
1.7.11.2