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make "--help" output work with help2man
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Closes: #606
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@umlaeute
umlaeute committed Nov 26, 2024
1 parent 57bef59 commit e750af9
Showing 1 changed file with 106 additions and 114 deletions.
220 changes: 106 additions & 114 deletions utils/v4l2loopback-ctl.c
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Original file line number Diff line number Diff line change
Expand Up @@ -290,112 +290,93 @@ typedef enum {
_UNKNOWN
} t_command;

static int help_shortcmdline(int detail, const char *program,
const char *argstring)
static void _help(int detail, const char *section, const char *program,
const char *verb, const char *argstring,
const char *description, const char *options)
{
dprintf(2, "\n");
dprintf(2, "\t");
dprintf(2, "%s %s\n", program, argstring);
return !detail;
(void)section;
if (!detail) {
dprintf(2, "%s%s%s %s\n", program ? program : "",
program ? " " : "", verb, argstring);
return;
}

dprintf(2, "\n%s%s%s %s:\n", program ? program : "", program ? " " : "",
verb, argstring);

dprintf(2, " %s\n ", description);

if (options) {
dprintf(2, "%s\n", options);
//dprintf(2, "\n\n'%s' OPTIONS:%s\n", verb, options);
}
}

static void help_list(const char *program, int detail)
{
if (detail)
dprintf(2, "\n listing devices ('list')"
"\n ========================");
if (help_shortcmdline(detail, program, "list {<flags>}"))
return;
dprintf(2,
"\n <flags>\tany of the following flags may be present"
"\n\t -e/--escape : escape control-characters in (device) names"
"\n\t -h/--help : print this help and exit"
"\n"
"\n \tlist all available loopback-devices"
"");
_help(detail, "Listing Devices", program, "list", "[OPTIONS]",
"list all available loopback-devices",
"\n\t-e, --escape escape control-characters in (device) names"
"\n\t-h, --help print this help and exit"
"");
}
static void help_add(const char *program, int detail)
{
if (detail)
dprintf(2, "\n adding devices ('add')"
"\n ======================");
if (help_shortcmdline(
detail, program,
"add {<flags>} [<outputdevice> [<capturedevice>]]"))
return;
dprintf(2,
"\n <flags>\tany of the following flags may be present"
"\n\t -n/--name <name> : pretty name for the device"
"\n\t --min-width <w> : minimum allowed frame width"
"\n\t -w/--max-width <w> : maximum allowed frame width"
"\n\t --min-height <w> : minimum allowed frame height"
"\n\t -h/--max-height <h> : maximum allowed frame height"
"\n\t -x/--exclusive-caps <x> : whether to announce OUTPUT/CAPTURE capabilities exclusively"
"\n\t -b/--buffers <num> : buffers to queue"
"\n\t -o/--max-openers <num> : maximum allowed concurrent openers"
"\n\t -v/--verbose : verbose mode (print properties of device after successfully creating it)"
"\n\t -?/--help : print this help and exit"
"\n"
"\n <outputdevice>\tif given, create a specific device (otherwise just create a free one)."
"\n \teither specify a device name (e.g. '/dev/video1') or a device number ('1')."
"\n <capturedevice>\tif given, use separate output & capture devices (otherwise they are the same).");
_help(detail, "Adding Devices", program, "add",
"[OPTIONS] [<outputdevice> [<capturedevice>]]",
"create/add a new loopback-device",
"\n\t-b <num>, --buffers <num> buffers to queue"
"\n\t-h <h>, --max-height <h> maximum allowed frame height"
"\n\t-n <name>, --name <name> pretty name for the device"
"\n\t-o <num>, --max-openers <num> maximum allowed concurrent openers"
"\n\t-v, --verbose verbose mode (print properties of device after successfully creating it)"
"\n\t-w <w>, --max-width <w> maximum allowed frame width"
"\n\t-x <x>, --exclusive-caps <x> whether to announce OUTPUT/CAPTURE capabilities exclusively"
"\n\t--min-width <w> minimum allowed frame width"
"\n\t--min-height <w> minimum allowed frame height"
"\n\t-?, --help print this help and exit"
"\n"
"\n <outputdevice>\tif given, create a specific device (otherwise just create a free one)."
"\n \teither specify a device name (e.g. '/dev/video1') or a device number ('1')."
"\n <capturedevice>\tif given, use separate output & capture devices (otherwise they are the same).");
}
static void help_delete(const char *program, int detail)
{
if (detail)
dprintf(2, "\n deleting devices ('delete')"
"\n ===========================");
if (help_shortcmdline(detail, program, "delete <device>"))
return;
dprintf(2,
"\n <device>\tcan be given one more more times (to delete multiple devices at once)."
"\n \teither specify a device name (e.g. '/dev/video1') or a device number ('1').");
_help(detail, "Deleting Devices", program, "delete", "<device>",
"delete/remove an unused loopback device",
"\n <device>\tcan be given one more more times (to delete multiple devices at once)."
"\n \teither specify a device name (e.g. '/dev/video1') or a device number ('1').");
}
static void help_query(const char *program, int detail)
{
if (detail)
dprintf(2, "\n querying devices ('query')"
"\n ==========================");
if (help_shortcmdline(detail, program, "query {<flags>} <device>"))
return;
dprintf(2,
"\n <flags>\tany of the following flags may be present"
"\n\t -e/--escape : escape control-characters in (device) names"
"\n\t -h/--help : print this help and exit"
"\n"
"\n <device>\tcan be given one more more times (to query multiple devices at once)."
"\n \teither specify a device name (e.g. '/dev/video1') or a device number ('1').");
_help(detail, "Querying Devices", program, "query",
"[OPTIONS] <device>", "query information about a loopback device",
"\n\t-e, --escape escape control-characters in (device) names"
"\n\t-h, --help print this help and exit"
"\n"
"\n <device>\tcan be given one more more times (to query multiple devices at once)."
"\n \teither specify a device name (e.g. '/dev/video1') or a device number ('1').");
}
static void help_setfps(const char *program, int detail)
{
if (detail)
dprintf(2, "\n setting framerate ('set-fps')"
"\n =============================");
if (help_shortcmdline(detail, program, "set-fps <device> <fps>"))
return;
dprintf(2,
"\n <device>\teither specify a device name (e.g. '/dev/video1') or a device number ('1')."
"\n <fps>\tframes per second, either as integer ('30') or fraction ('50/2').");
_help(detail, "Setting Framerate", program, "set-fps", "<device> <fps>",
"set the default framerate for a loopback device",
"\n <device>\teither specify a device name (e.g. '/dev/video1') or a device number ('1')."
"\n <fps>\tframes per second, either as integer ('30') or fraction ('50/2').");
}
static void help_getfps(const char *program, int detail)
{
if (detail)
dprintf(2, "\n getting framerate ('get-fps')"
"\n =============================");
if (help_shortcmdline(detail, program, "get-fps <device>"))
return;
_help(detail, "Getting Framerate", program, "get-fps", "<device>",
"query the framerate of a loopback device", 0);
}
static void help_setcaps(const char *program, int detail)
{
if (detail)
dprintf(2, "\n setting capabilities ('set-caps')"
"\n =================================");
if (help_shortcmdline(detail, program, "set-caps <device> <caps>"))
return;
dprintf(2,
"\n <device>\teither specify a device name (e.g. '/dev/video1') or a device number ('1')."
"\n <caps>\tformat specification as '<fourcc>:<width>x<height>@<fps>' (e.g. 'UYVY:1024x768@60/1')"
"\n \tunset the current caps with the special value 'any'"
"\n");
_help(detail, "Setting Capabilities", program, "set-caps",
"<device> <caps>",
"set format/dimension/framerate of a loopback device",
"\n <device>\teither specify a device name (e.g. '/dev/video1') or a device number ('1')."
"\n <caps>\tformat specification as '<fourcc>:<width>x<height>@<fps>' (e.g. 'UYVY:1024x768@60/1')"
"\n \tunset the current caps with the special value 'any'");
if (detail > 1) {
dprintf(2, "\nknown fourcc-codes"
"\n=================="
Expand All @@ -416,28 +397,21 @@ static void help_setcaps(const char *program, int detail)
}
static void help_getcaps(const char *program, int detail)
{
if (detail)
dprintf(2, "\n getting capabilities ('get-caps')"
"\n =================================");
if (help_shortcmdline(detail, program, "get-caps <device>"))
return;
_help(detail, "Getting Capabilities", program, "get-caps", "<device>",
"get current format/dimension/framerate of a loopback device", 0);
}
static void help_settimeoutimage(const char *program, int detail)
{
if (detail)
dprintf(2, "\n setting timeout image ('set-timeout-image')"
"\n ===========================================");
if (help_shortcmdline(detail, program,
"set-timeout-image {<flags>} <device> <image>"))
return;
dprintf(2,
"\n <flags>\tany of the following flags may be present"
"\n\t -t/--timeout <timeout> : timeout (in ms)"
"\n\t -v/--verbose : raise verbosity (print what is being done)"
"\n\t -h/--help : print this help and exit"
"\n"
"\n <device>\teither specify a device name (e.g. '/dev/video1') or a device number ('1')."
"\n <image>\timage file");
_help(detail, "Setting Timeout Image", program, "set-timeout-image",
"[OPTIONS] <device> <image>",
"set a fallback image to be used if a video producer does not send new frames in time.",
"\n <flags>\tany of the following flags may be present"
"\n\t-h, --help print this help and exit"
"\n\t-t <timeout>, --timeout <timeout> timeout (in ms)"
"\n\t-v, --verbose raise verbosity (print what is being done)"
"\n"
"\n <device>\teither specify a device name (e.g. '/dev/video1') or a device number ('1')."
"\n <image>\timage file");
}
static void help_none(const char *program, int detail)
{
Expand Down Expand Up @@ -473,23 +447,41 @@ static t_help get_help(t_command cmd)
static void help(const char *name, int status)
{
t_command cmd;
dprintf(2, "usage: %s [general commands]", name);
dprintf(2, "\n\n");
dprintf(2, "\n general commands"
"\n ================"
"\n\t-v/--version : print version and exit"
"\n\t-h/-?/--help : print this help and exit");
/* brief helps */
for (cmd = ADD; cmd < _UNKNOWN; cmd++)
get_help(cmd)("", 0);
dprintf(2, "\n\n");
dprintf(2, "Usage: %s [OPTIONS]\n", name);
for (cmd = ADD; cmd < _UNKNOWN; cmd++) {
t_help hlp = get_help(cmd);
if (help_none == hlp)
continue;
dprintf(2, " or: %s ", name);
hlp(0, 0);
}

dprintf(2, "\nManage v4l2 loopback devices.");
dprintf(2,
"\n"
"\nThe general invocation uses a verb (like 'add' or 'delete') that defines"
"\nan action to be executed. Each verb has their own options and arguments."
"\n"
"\nOptions:"
"\n\t-h, -?, --help: print this help and exit"
"\n\t-v, --version: print version and exit"
"\n\n");

/* long helps */
dprintf(2, "*Verbs and their arguments*\n");
for (cmd = ADD; cmd < _UNKNOWN; cmd++) {
get_help(cmd)(name, 1);
t_help hlp = get_help(cmd);
if (help_none == hlp)
continue;
hlp("v4l2loopback-ctl", 1);
dprintf(2, "\n\n");
}

dprintf(2,
"*Reporting Bugs*\n"
"\nIssue tracker: https://github.com/umlaeute/v4l2loopback/issues"
"\nSecurity Issue tracker: https://git.iem.at/zmoelnig/v4l2loopback/-/issues"
"\n\n");
exit(status);
}
static void usage(const char *name)
Expand Down

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