[systemd-devel] [PATCH] systemd-analyze: filter dot output with a regular expression

[Lukasz Stelmach]

W dniu 24.03.2013 18:33, Zbigniew Jędrzejewski-Szmek pisze:
> On Sun, Mar 24, 2013 at 01:32:41PM +0100, Łukasz Stelmach wrote:
>> Make "systemd-analyze dot" output only lines matching a regular
>> expression passed on the command line. Without the regular expression
>> print everything.
>> ---
>>
>> A graph created with the full output of dot is completely incomprehensible
>> on a regular system. It thus makes perfect sense IMHO to add filtering
>> to systemd-analyze instead of trying to use sed/grep/awk/perl to filter
>> the dependencies but preserving the first and last line with the braces.
> 
> What regexps could one use?

For example '\.taget.*\.target" picks up only dependencies between
targets. Quite useful for a novice.

Recently I've grepped for something like
'\.target.*\.target\|sda2\|home\.mount' to learn if some nasty hacks I
did actually fit before the targets I wanted.


>> This, of course, is the first attempt so any comments are more than
>> welcome.
>>
>>  src/analyze/systemd-analyze.c | 35 ++++++++++++++++++++++++++++-------
>>  1 file changed, 28 insertions(+), 7 deletions(-)
>>
>> diff --git a/src/analyze/systemd-analyze.c b/src/analyze/systemd-analyze.c
>> index 01bf55e..bddbeda 100644
>> --- a/src/analyze/systemd-analyze.c
>> +++ b/src/analyze/systemd-analyze.c
>> @@ -25,6 +25,9 @@
>>  #include <getopt.h>
>>  #include <locale.h>
>>  #include <sys/utsname.h>
>> +#include <sys/types.h>
>> +#include <regex.h>
>> +#include <string.h>
>>  
>>  #include "install.h"
>>  #include "log.h"
>> @@ -578,7 +581,7 @@ static int analyze_time(DBusConnection *bus) {
>>          return 0;
>>  }
>>  
>> -static int graph_one_property(const char *name, const char *prop, DBusMessageIter *iter) {
>> +static int graph_one_property(const char *name, const char *prop, DBusMessageIter *iter, regex_t* regexp) {
>>  
>>          static const char * const colors[] = {
>>                  "Requires",              "[color=\"black\"]",
>> @@ -591,6 +594,7 @@ static int graph_one_property(const char *name, const char *prop, DBusMessageIte
>>                  "After",                 "[color=\"green\"]"
>>          };
>>  
>> +        char buf[1024];
>>          const char *c = NULL;
>>          unsigned i;
>>  
>> @@ -624,14 +628,16 @@ static int graph_one_property(const char *name, const char *prop, DBusMessageIte
>>  
>>                          assert(dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_STRING);
>>                          dbus_message_iter_get_basic(&sub, &s);
>> -                        printf("\t\"%s\"->\"%s\" %s;\n", name, s, c);
>> +                        snprintf(buf, sizeof(buf), "\t\"%s\"->\"%s\" %s;", name, s, c);
>> +                        if (regexp == NULL || regexec(regexp, buf, 0, NULL, 0) == 0)
>> +                                puts(buf);
>>                  }
>>          }
>>  
>>          return 0;
>>  }
>>  
>> -static int graph_one(DBusConnection *bus, const struct unit_info *u) {
>> +static int graph_one(DBusConnection *bus, const struct unit_info *u, regex_t* regexp) {
>>          _cleanup_dbus_message_unref_ DBusMessage *reply = NULL;
>>          const char *interface = "org.freedesktop.systemd1.Unit";
>>          int r;
>> @@ -675,7 +681,7 @@ static int graph_one(DBusConnection *bus, const struct unit_info *u) {
>>                  }
>>  
>>                  dbus_message_iter_recurse(&sub2, &sub3);
>> -                r = graph_one_property(u->id, prop, &sub3);
>> +                r = graph_one_property(u->id, prop, &sub3, regexp);
>>                  if (r < 0)
>>                          return r;
>>          }
>> @@ -683,10 +689,12 @@ static int graph_one(DBusConnection *bus, const struct unit_info *u) {
>>          return 0;
>>  }
>>  
>> -static int dot(DBusConnection *bus) {
>> +static int dot(DBusConnection *bus, char* regexp_s) {
>>          _cleanup_dbus_message_unref_ DBusMessage *reply = NULL;
>>          DBusMessageIter iter, sub;
>>          int r;
>> +        regex_t regexp;
>> +        int use_regexp = 0;
>>  
>>          r = bus_method_call_with_reply(
>>                          bus,
>> @@ -707,6 +715,16 @@ static int dot(DBusConnection *bus) {
>>                  return -EIO;
>>          }
>>  
>> +        memset(&regexp, 0, sizeof(regexp));
>> +        if (regexp_s != NULL) {
>> +                r = regcomp(&regexp, regexp_s, REG_NOSUB);
>> +                if (r != 0) {
>> +                        log_error("Invalid regular expression.");
>> +                        return -EINVAL;
>> +                }
>> +                use_regexp = 1;
>> +        }
>> +
>>          printf("digraph systemd {\n");
>>  
>>          for (dbus_message_iter_recurse(&iter, &sub);
>> @@ -718,13 +736,16 @@ static int dot(DBusConnection *bus) {
>>                  if (r < 0)
>>                          return -EIO;
>>  
>> -                r = graph_one(bus, &u);
>> +                r = graph_one(bus, &u, use_regexp ? &regexp : NULL);
>>                  if (r < 0)
>>                          return r;
>>          }
>>  
>>          printf("}\n");
>>  
>> +        if (use_regexp)
>> +                regfree(&regexp);
>> +
>>          log_info("   Color legend: black     = Requires\n"
>>                   "                 dark blue = Requisite\n"
>>                   "                 dark grey = Wants\n"
>> @@ -844,7 +865,7 @@ int main(int argc, char *argv[]) {
>>          else if (streq(argv[optind], "plot"))
>>                  r = analyze_plot(bus);
>>          else if (streq(argv[optind], "dot"))
>> -                r = dot(bus);
>> +                r = dot(bus, argv[optind+1]);
>>          else
>>                  log_error("Unknown operation '%s'.", argv[optind]);
>>  
>> -- 
>> 1.8.1.5
>>
>> _______________________________________________
>> systemd-devel mailing list
>> systemd-devel at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/systemd-devel
>>
> 


-- 
Było mi bardzo miło.               Czwarta pospolita klęska, [...]
>Łukasz<                 Już nie katolicka lecz złodziejska.  (c)PP