[lttng-tools.git] / src / bin / lttng / commands / enable_channels.c

/*
 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; only version 2
 * of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#define _GNU_SOURCE
#include <popt.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <inttypes.h>

#include "../command.h"

static char *opt_channels;
static int opt_kernel;
static char *opt_session_name;
static int opt_userspace;
static struct lttng_channel chan;
#if 0
/* Not implemented yet */
static char *opt_cmd_name;
static pid_t opt_pid;
#endif

enum {
	OPT_HELP = 1,
	OPT_DISCARD,
	OPT_OVERWRITE,
	OPT_SUBBUF_SIZE,
	OPT_NUM_SUBBUF,
	OPT_SWITCH_TIMER,
	OPT_READ_TIMER,
	OPT_USERSPACE,
	OPT_LIST_OPTIONS,
};

static struct lttng_handle *handle;

static struct poptOption long_options[] = {
	/* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
	{"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
	{"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
	{"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
#if 0
	/* Not implemented yet */
	{"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, &opt_cmd_name, OPT_USERSPACE, 0, 0},
	{"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
#else
	{"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
#endif
	{"discard",        0,   POPT_ARG_NONE, 0, OPT_DISCARD, 0, 0},
	{"overwrite",      0,   POPT_ARG_NONE, 0, OPT_OVERWRITE, 0, 0},
	{"subbuf-size",    0,   POPT_ARG_DOUBLE, 0, OPT_SUBBUF_SIZE, 0, 0},
	{"num-subbuf",     0,   POPT_ARG_INT, 0, OPT_NUM_SUBBUF, 0, 0},
	{"switch-timer",   0,   POPT_ARG_INT, 0, OPT_SWITCH_TIMER, 0, 0},
	{"read-timer",     0,   POPT_ARG_INT, 0, OPT_READ_TIMER, 0, 0},
	{"list-options",   0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
	{0, 0, 0, 0, 0, 0, 0}
};

/*
 * usage
 */
static void usage(FILE *ofp)
{
	fprintf(ofp, "usage: lttng enable-channel NAME[,NAME2,...] [options] [channel_options]\n");
	fprintf(ofp, "\n");
	fprintf(ofp, "  -h, --help               Show this help\n");
	fprintf(ofp, "      --list-options       Simple listing of options\n");
	fprintf(ofp, "  -s, --session            Apply on session name\n");
	fprintf(ofp, "  -k, --kernel             Apply on the kernel tracer\n");
#if 0
	fprintf(ofp, "  -u, --userspace [CMD]    Apply for the user-space tracer\n");
	fprintf(ofp, "                           If no CMD, the domain used is UST global\n");
	fprintf(ofp, "                           or else the domain is UST EXEC_NAME\n");
	fprintf(ofp, "  -p, --pid PID            If -u, apply to specific PID (domain: UST PID)\n");
#else
	fprintf(ofp, "  -u, --userspace          Apply for the user-space tracer\n");
#endif
	fprintf(ofp, "\n");
	fprintf(ofp, "Channel options:\n");
	fprintf(ofp, "      --discard            Discard event when buffers are full%s\n",
		DEFAULT_CHANNEL_OVERWRITE ? "" : " (default)");
	fprintf(ofp, "      --overwrite          Flight recorder mode%s\n",
		DEFAULT_CHANNEL_OVERWRITE ? " (default)" : "");
	fprintf(ofp, "      --subbuf-size        Subbuffer size in bytes\n");
	fprintf(ofp, "                               (default: %u, kernel default: %u)\n",
		DEFAULT_CHANNEL_SUBBUF_SIZE,
		DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE);
	fprintf(ofp, "      --num-subbuf         Number of subbufers\n");
	fprintf(ofp, "                               (default: %u, kernel default: %u)\n",
		DEFAULT_CHANNEL_SUBBUF_NUM,
		DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM);
	fprintf(ofp, "      --switch-timer       Switch timer interval in usec (default: %u)\n",
		DEFAULT_CHANNEL_SWITCH_TIMER);
	fprintf(ofp, "      --read-timer         Read timer interval in usec (default: %u)\n",
		DEFAULT_CHANNEL_READ_TIMER);
	fprintf(ofp, "\n");
}

/*
 * Set default attributes depending on those already defined from the command
 * line.
 */
static void set_default_attr(struct lttng_domain *dom)
{
	struct lttng_channel_attr default_attr;

	/* Set attributes */
	lttng_channel_set_default_attr(dom, &default_attr);

	if (chan.attr.overwrite == -1) {
		chan.attr.overwrite = default_attr.overwrite;
	}
	if (chan.attr.subbuf_size == -1) {
		chan.attr.subbuf_size = default_attr.subbuf_size;
	}
	if (chan.attr.num_subbuf == -1) {
		chan.attr.num_subbuf = default_attr.num_subbuf;
	}
	if (chan.attr.switch_timer_interval == -1) {
		chan.attr.switch_timer_interval = default_attr.switch_timer_interval;
	}
	if (chan.attr.read_timer_interval == -1) {
		chan.attr.read_timer_interval = default_attr.read_timer_interval;
	}
	if (chan.attr.output == -1) {
		chan.attr.output = default_attr.output;
	}
}

/*
 * Adding channel using the lttng API.
 */
static int enable_channel(char *session_name)
{
	int ret = CMD_SUCCESS;
	char *channel_name;
	struct lttng_domain dom;

	/* Create lttng domain */
	if (opt_kernel) {
		dom.type = LTTNG_DOMAIN_KERNEL;
	} else if (opt_userspace) {
		dom.type = LTTNG_DOMAIN_UST;
	} else {
		ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
		ret = CMD_ERROR;
		goto error;
	}

	set_default_attr(&dom);

	handle = lttng_create_handle(session_name, &dom);
	if (handle == NULL) {
		ret = -1;
		goto error;
	}

	/* Strip channel list (format: chan1,chan2,...) */
	channel_name = strtok(opt_channels, ",");
	while (channel_name != NULL) {
		/* Copy channel name and normalize it */
		strncpy(chan.name, channel_name, NAME_MAX);
		chan.name[NAME_MAX - 1] = '\0';

		DBG("Enabling channel %s", channel_name);

		ret = lttng_enable_channel(handle, &chan);
		if (ret < 0) {
			goto error;
		} else {
			MSG("%s channel %s enabled for session %s",
					opt_kernel ? "Kernel" : "UST", channel_name,
					session_name);
		}

		/* Next event */
		channel_name = strtok(NULL, ",");
	}

error:
	lttng_destroy_handle(handle);

	return ret;
}

/*
 * Default value for channel configuration.
 */
static void init_channel_config(void)
{
	/*
	 * Put -1 everywhere so we can identify those set by the command line and
	 * those needed to be set by the default values.
	 */
	memset(&chan.attr, -1, sizeof(chan.attr));
}

/*
 * Add channel to trace session
 */
int cmd_enable_channels(int argc, const char **argv)
{
	int opt, ret = CMD_SUCCESS;
	static poptContext pc;
	char *session_name = NULL;

	init_channel_config();

	pc = poptGetContext(NULL, argc, argv, long_options, 0);
	poptReadDefaultConfig(pc, 0);

	while ((opt = poptGetNextOpt(pc)) != -1) {
		switch (opt) {
		case OPT_HELP:
			usage(stdout);
			goto end;
		case OPT_DISCARD:
			chan.attr.overwrite = 0;
			DBG("Channel set to discard");
			break;
		case OPT_OVERWRITE:
			chan.attr.overwrite = 1;
			DBG("Channel set to overwrite");
			break;
		case OPT_SUBBUF_SIZE:
			/* TODO Replace atol with strtol and check for errors */
			chan.attr.subbuf_size = atol(poptGetOptArg(pc));
			DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
			break;
		case OPT_NUM_SUBBUF:
			/* TODO Replace atoi with strtol and check for errors */
			chan.attr.num_subbuf = atoi(poptGetOptArg(pc));
			DBG("Channel subbuf num set to %" PRIu64, chan.attr.num_subbuf);
			break;
		case OPT_SWITCH_TIMER:
			/* TODO Replace atoi with strtol and check for errors */
			chan.attr.switch_timer_interval = atoi(poptGetOptArg(pc));
			DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
			break;
		case OPT_READ_TIMER:
			/* TODO Replace atoi with strtol and check for errors */
			chan.attr.read_timer_interval = atoi(poptGetOptArg(pc));
			DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
			break;
		case OPT_USERSPACE:
			opt_userspace = 1;
			break;
		case OPT_LIST_OPTIONS:
			list_cmd_options(stdout, long_options);
			goto end;
		default:
			usage(stderr);
			ret = CMD_UNDEFINED;
			goto end;
		}
	}

	opt_channels = (char*) poptGetArg(pc);
	if (opt_channels == NULL) {
		ERR("Missing channel name.\n");
		usage(stderr);
		ret = CMD_ERROR;
		goto end;
	}

	if (!opt_session_name) {
		session_name = get_session_name();
		if (session_name == NULL) {
			ret = CMD_ERROR;
			goto end;
		}
	} else {
		session_name = opt_session_name;
	}

	ret = enable_channel(session_name);

end:
	poptFreeContext(pc);
	return ret;
}
Commit	Line	Data
d36b8583 DG	1	/*
	2	* Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
82a3637f DG	6	* as published by the Free Software Foundation; only version 2
82a3637f DG	7	* of the License.
d36b8583 DG	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	17	*/
	18
	19	#define _GNU_SOURCE
	20	#include <popt.h>
	21	#include <stdio.h>
	22	#include <stdlib.h>
	23	#include <string.h>
	24	#include <sys/stat.h>
	25	#include <sys/types.h>
	26	#include <unistd.h>
5a0de755	27	#include <inttypes.h>
d36b8583	28
c399183f	29	#include "../command.h"
d36b8583 DG	30
d36b8583 DG	31	static char *opt_channels;
5edd7e09	32	static int opt_kernel;
5440dc42	33	static char *opt_session_name;
d36b8583	34	static int opt_userspace;
d78d6610 DG	35	static struct lttng_channel chan;
	36	#if 0
	37	/* Not implemented yet */
eeac7d46	38	static char *opt_cmd_name;
d36b8583	39	static pid_t opt_pid;
d78d6610	40	#endif
d36b8583 DG	41
	42	enum {
	43	OPT_HELP = 1,
7d29a247 DG	44	OPT_DISCARD,
	45	OPT_OVERWRITE,
	46	OPT_SUBBUF_SIZE,
	47	OPT_NUM_SUBBUF,
	48	OPT_SWITCH_TIMER,
	49	OPT_READ_TIMER,
d36b8583	50	OPT_USERSPACE,
679b4943	51	OPT_LIST_OPTIONS,
d36b8583 DG	52	};
d36b8583 DG	53
cd80958d DG	54	static struct lttng_handle *handle;
cd80958d DG	55
d36b8583 DG	56	static struct poptOption long_options[] = {
	57	/* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
	58	{"help", 'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
5440dc42	59	{"session", 's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
d36b8583	60	{"kernel", 'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
d78d6610 DG	61	#if 0
d78d6610 DG	62	/* Not implemented yet */
6caa2bcc	63	{"userspace", 'u', POPT_ARG_STRING \| POPT_ARGFLAG_OPTIONAL, &opt_cmd_name, OPT_USERSPACE, 0, 0},
d36b8583	64	{"pid", 'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
d78d6610 DG	65	#else
	66	{"userspace", 'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
	67	#endif
7d29a247 DG	68	{"discard", 0, POPT_ARG_NONE, 0, OPT_DISCARD, 0, 0},
7d29a247 DG	69	{"overwrite", 0, POPT_ARG_NONE, 0, OPT_OVERWRITE, 0, 0},
1b579521 DG	70	{"subbuf-size", 0, POPT_ARG_DOUBLE, 0, OPT_SUBBUF_SIZE, 0, 0},
	71	{"num-subbuf", 0, POPT_ARG_INT, 0, OPT_NUM_SUBBUF, 0, 0},
	72	{"switch-timer", 0, POPT_ARG_INT, 0, OPT_SWITCH_TIMER, 0, 0},
	73	{"read-timer", 0, POPT_ARG_INT, 0, OPT_READ_TIMER, 0, 0},
679b4943	74	{"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
d36b8583 DG	75	{0, 0, 0, 0, 0, 0, 0}
	76	};
	77
	78	/*
	79	* usage
	80	*/
	81	static void usage(FILE *ofp)
	82	{
7d29a247	83	fprintf(ofp, "usage: lttng enable-channel NAME[,NAME2,...] [options] [channel_options]\n");
d36b8583	84	fprintf(ofp, "\n");
7d29a247	85	fprintf(ofp, " -h, --help Show this help\n");
679b4943	86	fprintf(ofp, " --list-options Simple listing of options\n");
5440dc42	87	fprintf(ofp, " -s, --session Apply on session name\n");
7d29a247	88	fprintf(ofp, " -k, --kernel Apply on the kernel tracer\n");
d78d6610	89	#if 0
e14f64a8 DG	90	fprintf(ofp, " -u, --userspace [CMD] Apply for the user-space tracer\n");
	91	fprintf(ofp, " If no CMD, the domain used is UST global\n");
	92	fprintf(ofp, " or else the domain is UST EXEC_NAME\n");
	93	fprintf(ofp, " -p, --pid PID If -u, apply to specific PID (domain: UST PID)\n");
d78d6610 DG	94	#else
	95	fprintf(ofp, " -u, --userspace Apply for the user-space tracer\n");
	96	#endif
7d29a247 DG	97	fprintf(ofp, "\n");
7d29a247 DG	98	fprintf(ofp, "Channel options:\n");
cabd9892 MD	99	fprintf(ofp, " --discard Discard event when buffers are full%s\n",
	100	DEFAULT_CHANNEL_OVERWRITE ? "" : " (default)");
	101	fprintf(ofp, " --overwrite Flight recorder mode%s\n",
	102	DEFAULT_CHANNEL_OVERWRITE ? " (default)" : "");
	103	fprintf(ofp, " --subbuf-size Subbuffer size in bytes\n");
	104	fprintf(ofp, " (default: %u, kernel default: %u)\n",
	105	DEFAULT_CHANNEL_SUBBUF_SIZE,
	106	DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE);
	107	fprintf(ofp, " --num-subbuf Number of subbufers\n");
	108	fprintf(ofp, " (default: %u, kernel default: %u)\n",
	109	DEFAULT_CHANNEL_SUBBUF_NUM,
	110	DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM);
	111	fprintf(ofp, " --switch-timer Switch timer interval in usec (default: %u)\n",
	112	DEFAULT_CHANNEL_SWITCH_TIMER);
	113	fprintf(ofp, " --read-timer Read timer interval in usec (default: %u)\n",
	114	DEFAULT_CHANNEL_READ_TIMER);
d36b8583 DG	115	fprintf(ofp, "\n");
	116	}
	117
5edd7e09 DG	118	/*
	119	* Set default attributes depending on those already defined from the command
	120	* line.
	121	*/
	122	static void set_default_attr(struct lttng_domain *dom)
	123	{
	124	struct lttng_channel_attr default_attr;
	125
	126	/* Set attributes */
	127	lttng_channel_set_default_attr(dom, &default_attr);
	128
	129	if (chan.attr.overwrite == -1) {
	130	chan.attr.overwrite = default_attr.overwrite;
	131	}
	132	if (chan.attr.subbuf_size == -1) {
	133	chan.attr.subbuf_size = default_attr.subbuf_size;
	134	}
	135	if (chan.attr.num_subbuf == -1) {
	136	chan.attr.num_subbuf = default_attr.num_subbuf;
	137	}
	138	if (chan.attr.switch_timer_interval == -1) {
	139	chan.attr.switch_timer_interval = default_attr.switch_timer_interval;
	140	}
	141	if (chan.attr.read_timer_interval == -1) {
	142	chan.attr.read_timer_interval = default_attr.read_timer_interval;
	143	}
	144	if (chan.attr.output == -1) {
	145	chan.attr.output = default_attr.output;
	146	}
	147	}
	148
d36b8583	149	/*
0fdd1e2c	150	* Adding channel using the lttng API.
d36b8583	151	*/
cd80958d	152	static int enable_channel(char *session_name)
d36b8583 DG	153	{
	154	int ret = CMD_SUCCESS;
	155	char *channel_name;
7d29a247	156	struct lttng_domain dom;
d36b8583	157
d78d6610	158	/* Create lttng domain */
7d29a247 DG	159	if (opt_kernel) {
7d29a247 DG	160	dom.type = LTTNG_DOMAIN_KERNEL;
d78d6610	161	} else if (opt_userspace) {
f6a9efaa	162	dom.type = LTTNG_DOMAIN_UST;
0fdd1e2c	163	} else {
e14f64a8	164	ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
d16c1a4c	165	ret = CMD_ERROR;
0fdd1e2c	166	goto error;
7d29a247 DG	167	}
7d29a247 DG	168
5edd7e09 DG	169	set_default_attr(&dom);
5edd7e09 DG	170
cd80958d DG	171	handle = lttng_create_handle(session_name, &dom);
	172	if (handle == NULL) {
	173	ret = -1;
	174	goto error;
	175	}
	176
0fdd1e2c	177	/* Strip channel list (format: chan1,chan2,...) */
d36b8583 DG	178	channel_name = strtok(opt_channels, ",");
d36b8583 DG	179	while (channel_name != NULL) {
0fdd1e2c DG	180	/* Copy channel name and normalize it */
	181	strncpy(chan.name, channel_name, NAME_MAX);
	182	chan.name[NAME_MAX - 1] = '\0';
	183
	184	DBG("Enabling channel %s", channel_name);
	185
	186	ret = lttng_enable_channel(handle, &chan);
	187	if (ret < 0) {
d36b8583 DG	188	goto error;
d36b8583 DG	189	} else {
7885e399 DG	190	MSG("%s channel %s enabled for session %s",
	191	opt_kernel ? "Kernel" : "UST", channel_name,
	192	session_name);
d36b8583 DG	193	}
	194
	195	/* Next event */
	196	channel_name = strtok(NULL, ",");
	197	}
	198
	199	error:
cd80958d DG	200	lttng_destroy_handle(handle);
cd80958d DG	201
d36b8583 DG	202	return ret;
	203	}
	204
	205	/*
0fdd1e2c	206	* Default value for channel configuration.
7d29a247 DG	207	*/
	208	static void init_channel_config(void)
	209	{
5edd7e09 DG	210	/*
	211	* Put -1 everywhere so we can identify those set by the command line and
	212	* those needed to be set by the default values.
	213	*/
	214	memset(&chan.attr, -1, sizeof(chan.attr));
7d29a247 DG	215	}
	216
	217	/*
0fdd1e2c	218	* Add channel to trace session
d36b8583 DG	219	*/
	220	int cmd_enable_channels(int argc, const char **argv)
	221	{
ca1c3607	222	int opt, ret = CMD_SUCCESS;
d36b8583	223	static poptContext pc;
cd80958d	224	char *session_name = NULL;
d36b8583	225
7d29a247 DG	226	init_channel_config();
7d29a247 DG	227
d36b8583 DG	228	pc = poptGetContext(NULL, argc, argv, long_options, 0);
	229	poptReadDefaultConfig(pc, 0);
	230
	231	while ((opt = poptGetNextOpt(pc)) != -1) {
	232	switch (opt) {
	233	case OPT_HELP:
ca1c3607	234	usage(stdout);
d36b8583	235	goto end;
7d29a247 DG	236	case OPT_DISCARD:
	237	chan.attr.overwrite = 0;
	238	DBG("Channel set to discard");
	239	break;
	240	case OPT_OVERWRITE:
	241	chan.attr.overwrite = 1;
	242	DBG("Channel set to overwrite");
	243	break;
	244	case OPT_SUBBUF_SIZE:
ca1c3607	245	/* TODO Replace atol with strtol and check for errors */
7d29a247	246	chan.attr.subbuf_size = atol(poptGetOptArg(pc));
5a0de755	247	DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
7d29a247 DG	248	break;
7d29a247 DG	249	case OPT_NUM_SUBBUF:
ca1c3607	250	/* TODO Replace atoi with strtol and check for errors */
7d29a247	251	chan.attr.num_subbuf = atoi(poptGetOptArg(pc));
5a0de755	252	DBG("Channel subbuf num set to %" PRIu64, chan.attr.num_subbuf);
7d29a247 DG	253	break;
7d29a247 DG	254	case OPT_SWITCH_TIMER:
ca1c3607	255	/* TODO Replace atoi with strtol and check for errors */
7d29a247 DG	256	chan.attr.switch_timer_interval = atoi(poptGetOptArg(pc));
	257	DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
	258	break;
	259	case OPT_READ_TIMER:
ca1c3607	260	/* TODO Replace atoi with strtol and check for errors */
7d29a247 DG	261	chan.attr.read_timer_interval = atoi(poptGetOptArg(pc));
7d29a247 DG	262	DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
d36b8583	263	break;
eeac7d46 MD	264	case OPT_USERSPACE:
eeac7d46 MD	265	opt_userspace = 1;
eeac7d46	266	break;
679b4943 SM	267	case OPT_LIST_OPTIONS:
679b4943 SM	268	list_cmd_options(stdout, long_options);
679b4943	269	goto end;
d36b8583 DG	270	default:
	271	usage(stderr);
	272	ret = CMD_UNDEFINED;
	273	goto end;
	274	}
	275	}
	276
	277	opt_channels = (char*) poptGetArg(pc);
	278	if (opt_channels == NULL) {
7d29a247	279	ERR("Missing channel name.\n");
d36b8583	280	usage(stderr);
ca1c3607	281	ret = CMD_ERROR;
d36b8583 DG	282	goto end;
	283	}
	284
cd80958d DG	285	if (!opt_session_name) {
	286	session_name = get_session_name();
	287	if (session_name == NULL) {
ca1c3607	288	ret = CMD_ERROR;
cd80958d DG	289	goto end;
	290	}
	291	} else {
	292	session_name = opt_session_name;
	293	}
	294
	295	ret = enable_channel(session_name);
d36b8583 DG	296
d36b8583 DG	297	end:
ca1c3607	298	poptFreeContext(pc);
d36b8583 DG	299	return ret;
d36b8583 DG	300	}