Add simple usage message to systemd-backlight (#16709)

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Plan C 2020-08-28 19:50:35 +08:00 committed by GitHub
parent 677bb0555a
commit b23728ec9f
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2 changed files with 30 additions and 1 deletions

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@ -23,7 +23,8 @@
<refsynopsisdiv>
<para><filename>systemd-backlight@.service</filename></para>
<para><filename>/usr/lib/systemd/systemd-backlight</filename></para>
<para><filename>/usr/lib/systemd/systemd-backlight</filename> save [backlight|leds]:DEVICE</para>
<para><filename>/usr/lib/systemd/systemd-backlight</filename> load [backlight|leds]:DEVICE</para>
</refsynopsisdiv>
<refsect1>

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@ -13,11 +13,36 @@
#include "main-func.h"
#include "mkdir.h"
#include "parse-util.h"
#include "pretty-print.h"
#include "terminal-util.h"
#include "reboot-util.h"
#include "string-util.h"
#include "strv.h"
#include "util.h"
static int help(void) {
_cleanup_free_ char *link = NULL;
int r;
r = terminal_urlify_man("systemd-backlight", "8", &link);
if (r < 0)
return log_oom();
printf("%s save [backlight|leds]:DEVICE\n"
"%s load [backlight|leds]:DEVICE\n"
"\n%sSave and restore backlight brightness at shutdown and boot.%s\n\n"
" save Save current brightness\n"
" load Set brightness to be the previously saved value\n"
"\nSee the %s for details.\n"
, program_invocation_short_name
, program_invocation_short_name
, ansi_highlight(), ansi_normal()
, link
);
return 0;
}
static int find_pci_or_platform_parent(sd_device *device, sd_device **ret) {
const char *subsystem, *sysname, *value;
sd_device *parent;
@ -334,6 +359,9 @@ static int run(int argc, char *argv[]) {
log_setup_service();
if (strv_contains(strv_skip(argv, 1), "--help"))
return help();
if (argc != 3)
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program requires two arguments.");