1page.title=Android Debug Bridge 2@jd:body 3 4<div id="qv-wrapper"> 5<div id="qv"> 6 <h2>ADB quickview</h2> 7 <ul> 8<li>Manage the state of an emulator or device</li> 9<li>Run shell commands on a device</li> 10<li>Manage port forwarding on an emulator or device</li> 11<li>Copy files to/from an emulator or device</li> 12 </ul> 13 14 <h2>In this document</h2> 15 <ol> 16<li><a href="#issuingcommands">Issuing ADB Commands</a></li> 17<li><a href="#devicestatus">Querying for Emulator/Device Instances</a></li> 18<li><a href="#directingcommands">Directing Commands to a Specific Emulator/Device Instance</a></li> 19<li><a href="#move">Installing an Application</a></li> 20<li><a href="#forwardports">Forwarding Ports</a></li> 21<li><a href="#copyfiles">Copying Files to or from an Emulator/Device Instance</a></li> 22<li><a href="#commandsummary">Listing of adb Commands </a></li> 23<li><a href="#shellcommands">Issuing Shell Commands</a></li> 24<li><a href="#logcat">Enabling logcat Logging</a></li> 25<li><a href="#stopping">Stopping the adb Server</a></li> 26 </ol> 27 28 <h2>See also</h2> 29 <ol> 30 <li><a href="emulator.html">Emulator</a></li> 31 </ol> 32 33</div> 34</div> 35 36<!-- 37<p>Android Debug Bridge (adb) is a versatile tool that </a>. </p> 38 39<p>Some of ways you can use adb include:</p> 40 41<ul> 42 43</ul> 44<p>The sections below introduce adb and describe many of its common uses. </p> 45 46<h2>Contents</h2> 47<dl> 48<dt><a href="#overview">Overview</a></dt> 49<dt><a href="#issuingcommands">Issuing adb Commands</a></dt> 50<dt><a href="#devicestatus">Querying for Emulator/Device Instances</a></dt> 51<dt><a href="#directingcommands">Directing Commands to a Specific Emulator/Device Instance</a></dt> 52<dt><a href="#move">Installing an Application</a></dt> 53<dt><a href="#forwardports">Forwarding Ports</a></dt> 54<dt><a href="#copyfiles">Copying Files to or from an Emulator/Device Instance</a></dt> 55<dt><a href="#commandsummary">Listing of adb Commands </a></dt> 56<dt><a href="#shellcommands">Issuing Shell Commands</a></dt> 57 <dd><a href="#sqlite">Examining sqlite3 Databases from a Remote Shell</a></dd> 58 <dd><a href="#monkey">UI/Application Exerciser Monkey</a></dd> 59 <dd><a href="#othershellcommands">Other Shell Commands</a></dd> 60<dt><a href="#logcat">Enabling logcat Logging</a> </dt> 61 <dd><a href="#usinglogcat">Using logcat Commands</a></dd> 62 <dd><a href="#filteringoutput">Filtering Log Output</a></dd> 63 <dd><a href="#outputformat">Controlling Log Output Format</a></dd> 64 <dd><a href="#alternativebuffers">Viewing Alternative Log Buffers</a></dd> 65 <dd><a href="#stdout">Viewing stdout and stderr</a></dd> 66 <dd><a href="#logcatoptions">Listing of logcat Command Options</a></dd> 67<dt><a href="#stopping">Stopping the adb Server</a> </dt> 68</dl> 69 70<a name="overview"></a> 71 72<h2>Overview</h2> 73--> 74<p>Android Debug Bridge (adb) is a versatile tool lets you manage the state of an emulator instance or Android-powered device. It is a client-server program that includes three components: </p> 75 76<ul> 77 <li>A client, which runs on your development machine. You can invoke a client from a shell by issuing an adb command. Other Android tools such as the ADT plugin and DDMS also create adb clients. </li> 78 <li>A server, which runs as a background process on your development machine. The server manages communication between the client and the adb daemon running on an emulator or device. </li> 79 <li>A daemon, which runs as a background process on each emulator or device instance. </li> 80</ul> 81 82<p>You can find the {@code adb} tool in {@code <sdk>/platform-tools/}.</p> 83 84<p>When you start an adb client, the client first checks whether there is an adb server process already running. If there isn't, it starts the server process. When the server starts, it binds to local TCP port 5037 and listens for commands sent from adb clients—all adb clients use port 5037 to communicate with the adb server. </p> 85 86<p>The server then sets up connections to all running emulator/device instances. It locates emulator/device instances by scanning odd-numbered ports in the range 5555 to 5585, the range used by emulators/devices. Where the server finds an adb daemon, it sets up a connection to that port. Note that each emulator/device instance acquires a pair of sequential ports — an even-numbered port for console connections and an odd-numbered port for adb connections. For example: </p> 87 88<p style="margin-left:2em"> 89Emulator 1, console: 5554<br/> 90Emulator 1, adb: 5555<br> 91Emulator 2, console: 5556<br> 92Emulator 2, adb: 5557 ... 93</p> 94 95<p>As shown, the emulator instance connected to adb on port 5555 is the same as the instance whose console listens on port 5554. </p> 96 97<p>Once the server has set up connections to all emulator instances, you can use adb commands to control and access those instances. Because the server manages connections to emulator/device instances and handles commands from multiple adb clients, you can control any emulator/device instance from any client (or from a script).</p> 98 99<p>The sections below describe the commands that you can use to access adb capabilities and manage the state of an emulator/device. Note that if you are developing Android applications in Eclipse and have installed the ADT plugin, you do not need to access adb from the command line. The ADT plugin provides a transparent integration of adb into the Eclipse IDE. However, you can still use adb directly as necessary, such as for debugging.</p> 100 101<a name="issuingcommands"></a> 102 103<h2>Issuing adb Commands</h2> 104 105<p>You can issue adb commands from a command line on your development machine or from a script. The usage is: </p> 106 107 <pre>adb [-d|-e|-s <serialNumber>] <command> </pre> 108 109<p>When you issue a command, the program invokes an adb client. The client is not specifically associated with any emulator instance, so if multiple emulators/devices are running, you need to use the <code>-d</code> option to specify the target instance to which the command should be directed. For more information about using this option, see <a href="#directingcommands">Directing Commands to a Specific Emulator/Device Instance</a>. </p> 110 111<a name="devicestatus"></a> 112 113<h2>Querying for Emulator/Device Instances</h2> 114 115<p>Before issuing adb commands, it is helpful to know what emulator/device instances are connected to the adb server. You can generate a list of attached emulators/devices using the <code>devices</code> command: </p> 116 117 <pre>adb devices</pre> 118 119<p>In response, adb prints this status information for each instance:</p> 120 121<ul> 122 <li>Serial number — A string created by adb to uniquely identify an emulator/device instance by its 123 console port number. The format of the serial number is <code><type>-<consolePort></code>. 124 Here's an example serial number: <code>emulator-5554</code></li> 125 <li>State — The connection state of the instance. Three states are supported: 126 <ul> 127 <li><code>offline</code> — the instance is not connected to adb or is not responding.</li> 128 <li><code>device</code> — the instance is now connected to the adb server. Note that this state does not 129 imply that the Android system is fully booted and operational, since the instance connects to adb 130 while the system is still booting. However, after boot-up, this is the normal operational state of 131 an emulator/device instance.</li> 132 </ul> 133 </li> 134</ul> 135 136<p>The output for each instance is formatted like this: </p> 137 138 <pre>[serialNumber] [state]</pre> 139 140<p>Here's an example showing the <code>devices</code> command and its output:</p> 141 142 <pre>$ adb devices 143List of devices attached 144emulator-5554 device 145emulator-5556 device 146emulator-5558 device</pre> 147 148<p>If there is no emulator/device running, adb returns <code>no device</code>.</p> 149 150 151<a name="directingcommands"></a> 152 153<h2>Directing Commands to a Specific Emulator/Device Instance</h2> 154 155<p>If multiple emulator/device instances are running, you need to specify a target instance when issuing adb commands. To so so, use the <code>-s</code> option in the commands. The usage for the <code>-s</code> option is:</p> 156 157 <pre>adb -s <serialNumber> <command> </pre> 158 159<p>As shown, you specify the target instance for a command using its adb-assigned serial number. You can use the <code>devices</code> command to obtain the serial numbers of running emulator/device instances. </p> 160 161<p>Here is an example: </p> 162 163 <pre>adb -s emulator-5556 install helloWorld.apk</pre> 164 165<p>Note that, if you issue a command without specifying a target emulator/device instance using <code>-s</code>, adb generates an error. 166 167<a name="move"></a> 168 169<h2>Installing an Application</h2> 170<p>You can use adb to copy an application from your development computer and install it on an emulator/device instance. To do so, use the <code>install</code> command. With the command, you must specify the path to the .apk file that you want to install:</p> 171 172<pre>adb install <path_to_apk></pre> 173 174<p>For more information about how to create an .apk file that you can install on an emulator/device instance, see <a href="{@docRoot}guide/developing/tools/aapt.html">Android Asset Packaging Tool</a> (aapt). </p> 175 176<p>Note that, if you are using the Eclipse IDE and have the ADT plugin installed, you do not need to use adb (or aapt) directly to install your application on the emulator/device. Instead, the ADT plugin handles the packaging and installation of the application for you. </p> 177 178 179<a name="forwardports"></a> 180 181<h2>Forwarding Ports</h2> 182 183 <p>You can use the <code>forward</code> command to set up arbitrary port forwarding — forwarding of requests on a specific host port to a different port on an emulator/device instance. Here's how you would set up forwarding of host port 6100 to emulator/device port 7100:</p> 184<pre>adb forward tcp:6100 tcp:7100</pre> 185 <p>You can also use adb to set up forwarding to named abstract UNIX domain sockets, as illustrated here:</p> 186<pre>adb forward tcp:6100 local:logd </pre> 187 188<a name="copyfiles"></a> 189 190<h2>Copying Files to or from an Emulator/Device Instance</h2> 191 192<p>You can use the adb commands <code>pull</code> and <code>push</code> to copy files to and from an emulator/device instance's data file. Unlike the <code>install</code> command, which only copies an .apk file to a specific location, the <code>pull</code> and <code>push</code> commands let you copy arbitrary directories and files to any location in an emulator/device instance. </p> 193 194<p>To copy a file or directory (recursively) <em>from</em> the emulator or device, use</p> 195<pre>adb pull <remote> <local></pre> 196 197<p>To copy a file or directory (recursively) <em>to</em> the emulator or device, use</p> 198 <pre>adb push <local> <remote></pre> 199 200<p>In the commands, <code><local></code> and <code><remote></code> refer to the paths to the target files/directory on your development machine (local) and on the emulator/device instance (remote).</p> 201 202<p>Here's an example: </p> 203<pre>adb push foo.txt /sdcard/foo.txt</pre> 204 205<a name="commandsummary"></a> 206 207<h2>Listing of adb Commands</h2> 208 209<p>The table below lists all of the supported adb commands and explains their meaning and usage. </p> 210 211 212<table> 213<tr> 214 <th>Category</th> 215 <th>Command</th> 216 <th>Description</th> 217 <th>Comments</th> 218</tr> 219 220<tr> 221<td rowspan="3">Options</td> 222<td><code>-d</code></td> 223<td>Direct an adb command to the only attached USB device.</td> 224<td>Returns an error if more than one USB device is attached.</td> 225</tr> 226 227<tr> 228<td><code>-e</code></td> 229<td>Direct an adb command to the only running emulator instance.</td> 230<td>Returns an error if more than one emulator instance is running. </td> 231</tr> 232 233<tr> 234<td><code>-s <serialNumber></code></td> 235<td>Direct an adb command a specific emulator/device instance, referred to by its adb-assigned serial number (such as "emulator-5556").</td> 236<td>If not specified, adb generates an error.</td> 237</tr> 238 239<tr> 240<td rowspan="3">General</td> 241<td><code>devices</code></td> 242<td>Prints a list of all attached emulator/device instances.</td> 243<td>See <a href="#devicestatus">Querying for Emulator/Device Instances</a> for more information.</td> 244</tr> 245 246<tr> 247<td><code>help</code></td> 248<td>Prints a list of supported adb commands.</td> 249<td> </td> 250</tr> 251 252<tr> 253<td><code>version</code></td> 254<td>Prints the adb version number. </td> 255<td> </td> 256</tr> 257 258<tr> 259<td rowspan="3">Debug</td> 260<td ><code>logcat [<option>] [<filter-specs>]</code></td> 261<td>Prints log data to the screen. </td> 262<td> </td> 263</tr> 264 265<tr> 266<td><code>bugreport</code></td> 267<td>Prints <code>dumpsys</code>, <code>dumpstate</code>, and <code>logcat</code> data to the screen, for the purposes of bug reporting. </td> 268<td> </td> 269</tr> 270 271<tr> 272<td><code>jdwp</code></td> 273<td>Prints a list of available JDWP processes on a given device. </td> 274<td>You can use the <code>forward jdwp:<pid></code> port-forwarding specification to connect to a specific JDWP process. For example: <br> 275 <code>adb forward tcp:8000 jdwp:472</code><br> 276 <code>jdb -attach localhost:8000</code></p> 277 </td> 278</tr> 279 280<tr> 281<td rowspan=3">Data</td> 282<td><code>install <path-to-apk></code></td> 283<td>Pushes an Android application (specified as a full path to an .apk file) to the data file of an emulator/device. </td> 284<td> </td> 285</tr> 286 287<tr> 288<td><code>pull <remote> <local></code></td> 289<td>Copies a specified file from an emulator/device instance to your development computer. </td> 290<td> </td> 291</tr> 292 293<tr> 294<td><code>push <local> <remote></code></td> 295<td>Copies a specified file from your development computer to an emulator/device instance. </td> 296<td> </td> 297</tr> 298 299<tr> 300<td rowspan="2">Ports and Networking</td> 301<td><code>forward <local> <remote></code></td> 302<td>Forwards socket connections from a specified local port to a specified remote port on the emulator/device instance. </td> 303<td>Port specifications can use these schemes: 304<ul><li><code>tcp:<portnum></code></li> 305<li><code>local:<UNIX domain socket name></code></li> 306<li><code>dev:<character device name></code></li> 307<li><code>jdwp:<pid></code></li></ul> 308</td> 309</tr> 310 311<tr> 312<td><code>ppp <tty> [parm]...</code></td> 313<td>Run PPP over USB. 314<ul> 315<li><code><tty></code> — the tty for PPP stream. For example <code>dev:/dev/omap_csmi_ttyl</code>. </li> 316<li><code>[parm]... </code> &mdash zero or more PPP/PPPD options, such as <code>defaultroute</code>, <code>local</code>, <code>notty</code>, etc.</li></ul> 317 318<p>Note that you should not automatically start a PPP connection. </p></td> 319<td></td> 320</tr> 321 322<tr> 323<td rowspan="3">Scripting</td> 324<td><code>get-serialno</code></td> 325<td>Prints the adb instance serial number string.</td> 326<td rowspan="2">See <a href="#devicestatus">Querying for Emulator/Device Instances</a> for more information. </td> 327</tr> 328 329<tr> 330<td><code>get-state</code></td> 331<td>Prints the adb state of an emulator/device instance.</td> 332</td> 333</tr> 334 335<tr> 336<td><code>wait-for-device</code></td> 337<td>Blocks execution until the device is online — that is, until the instance state is <code>device</code>.</td> 338<td>You can prepend this command to other adb commands, in which case adb will wait until the emulator/device instance is connected before issuing the other commands. Here's an example: 339<pre>adb wait-for-device shell getprop</pre> 340 341Note that this command does <em>not</em> cause adb to wait until the entire system is fully booted. For that reason, you should not prepend it to other commands that require a fully booted system. As an example, the <code>install</code> requires the Android package manager, which is available only after the system is fully booted. A command such as 342 343<pre>adb wait-for-device install <app>.apk</pre> 344 345would issue the <code>install</code> command as soon as the emulator or device instance connected to the adb server, but before the Android system was fully booted, so it would result in an error. </td> 346</tr> 347 348 349 350<tr> 351<td rowspan="2">Server</td> 352<td><code>start-server</code></td> 353<td>Checks whether the adb server process is running and starts it, if not.</td> 354<td> </td> 355</tr> 356 357<tr> 358<td><code>kill-server</code></td> 359<td>Terminates the adb server process.</td> 360<td> </td> 361</tr> 362 363 364 365<tr> 366<td rowspan="2">Shell</td> 367<td><code>shell</code></td> 368<td>Starts a remote shell in the target emulator/device instance.</td> 369<td rowspan="2">See <a href="#shellcommands">Issuing Shell Commands</a> for more information. </td> 370</tr> 371 372<tr> 373<td><code>shell [<shellCommand>]</code></td> 374<td>Issues a shell command in the target emulator/device instance and then exits the remote shell.</td> 375</tr> 376 377</table> 378 379 380<a name="shellcommands"></a> 381 382<h2>Issuing Shell Commands</h2> 383 384<p>Adb provides an ash shell that you can use to run a variety of commands on an emulator 385or device. The command binaries are stored in the file system of the emulator or device, 386in this location: </p> 387 388<pre>/system/bin/...</pre> 389 390<p>You can use the <code>shell</code> command to issue commands, with or without entering the adb remote shell on the emulator/device. </p> 391 392<p>To issue a single command without entering a remote shell, use the <code>shell</code> command like this: </p> 393 394 <pre>adb [-d|-e|-s {<serialNumber>}] shell <shellCommand></pre> 395 396<p>To drop into a remote shell on a emulator/device instance, use the <code>shell</code> command like this:</p> 397 398 <pre>adb [-d|-e|-s {<serialNumber>}] shell</pre> 399 400<p>When you are ready to exit the remote shell, use <code>CTRL+D</code> or <code>exit</code> to end the shell session. </p> 401 402<p>The sections below provide more information about shell commands that you can use.</p> 403 404<a name="sqlite" id="sqlite"></a> 405 406<h3>Examining sqlite3 Databases from a Remote Shell</h3> 407 408<p>From an adb remote shell, you can use the 409<a href="http://www.sqlite.org/sqlite.html">sqlite3</a> command-line program to 410manage SQLite databases created by Android applications. The 411<code>sqlite3</code> tool includes many useful commands, such as 412<code>.dump</code> to print out the contents of a table and 413<code>.schema</code> to print the SQL CREATE statement for an existing table. 414The tool also gives you the ability to execute SQLite commands on the fly.</p> 415 416<p>To use <code>sqlite3</code>, enter a remote shell on the emulator instance, as described above, then invoke the tool using the <code>sqlite3</code> command. Optionally, when invoking <code>sqlite3</code> you can specify the full path to the database you want to explore. Emulator/device instances store SQLite3 databases in the folder <code><span chatdir="1"><span chatindex="259474B4B070F261">/data/data/<em><package_name></em>/databases</span></span>/</code>. </p> 417 418<p>Here's an example: </p> 419 420<pre>$ adb -s emulator-5554 shell 421# sqlite3 /data/data/com.example.google.rss.rssexample/databases/rssitems.db 422SQLite version 3.3.12 423Enter ".help" for instructions 424<em>.... enter commands, then quit...</em> 425sqlite> .exit </pre> 426 427<p>Once you've invoked <code>sqlite3</code>, you can issue <code>sqlite3</code> commands in the shell. To exit and return to the adb remote shell, use <code>exit</code> or <code>CTRL+D</code>. 428 429 430<a name="monkey"></a> 431 432<h3>UI/Application Exerciser Monkey</h3> 433 434<p>The Monkey is a program that runs on your emulator or device and generates pseudo-random 435streams of user events such as clicks, touches, or gestures, as well as a number of system-level 436events. You can use the Monkey to stress-test applications that you are developing, 437in a random yet repeatable manner.</p> 438 439<p>The simplest way to use the monkey is with the following command, which will launch your 440application and send 500 pseudo-random events to it.</p> 441 442<pre>$ adb shell monkey -v -p your.package.name 500</pre> 443 444<p>For more information about command options for Monkey, see the complete 445<a href="{@docRoot}guide/developing/tools/monkey.html" title="monkey">UI/Application Exerciser Monkey</a> documentation page.</p> 446 447 448<a name="othershellcommands"></a> 449 450<h3>Other Shell Commands</h3> 451 452<p>The table below lists several of the adb shell commands available. For a complete list of commands and programs, start an emulator instance and use the <code>adb -help</code> command. </p> 453 454<pre>adb shell ls /system/bin</pre> 455 456<p>Help is available for most of the commands. </p> 457 458<table> 459<tr> 460 <th>Shell Command</th> 461 <th>Description</th> 462 <th>Comments</th> 463</tr> 464 465<tr> 466<td><code>dumpsys</code></td> 467<td>Dumps system data to the screen.</td> 468<td rowspan=4">The <a href="{@docRoot}guide/developing/tools/ddms.html">Dalvik Debug Monitor Service</a> (DDMS) tool offers integrated debug environment that you may find easier to use.</td> 469</tr> 470 471<tr> 472<td><code>dumpstate</code></td> 473<td>Dumps state to a file.</td> 474</tr> 475 476<tr> 477<td><code>logcat [<option>]... [<filter-spec>]...</code></td> 478<td>Enables radio logging and prints output to the screen. </td> 479</tr> 480 481<tr> 482<td><code>dmesg</code></td> 483<td>Prints kernel debugging messages to the screen. </td> 484</tr> 485 486<tr> 487<td><code>start</code></td> 488<td>Starts (restarts) an emulator/device instance.</td> 489<td> </td> 490</tr> 491 492<tr> 493<td><code>stop</code></td> 494<td>Stops execution of an emulator/device instance.</td> 495<td> </td> 496</tr> 497 498</table> 499 500<a name="logcat"></a> 501 502<h2>Enabling logcat Logging</h2> 503 504<p>The Android logging system provides a mechanism for collecting and viewing system debug output. Logs from various applications and portions of the system are collected in a series of circular buffers, which then can be viewed and filtered by the <code>logcat</code> command.</p> 505 506<a name="usinglogcat"></a> 507 508<h3>Using logcat Commands</h3> 509 510<p>You can use the <code>logcat</code> command to view and follow the contents of the system's log buffers. The general usage is:</p> 511 512<pre>[adb] logcat [<option>] ... [<filter-spec>] ...</pre> 513 514<p>The sections below explain filter specifications and the command options. See <a href="#logcatoptions">Listing of logcat Command Options</a> for a summary of options. </p> 515 516<p>You can use the <code>logcat</code> command from your development computer or from a remote adb shell in an emulator/device instance. To view log output in your development computer, you use</p> 517 518<pre>$ adb logcat</pre> 519 520<p>and from a remote adb shell you use</p> 521 522<pre># logcat</pre> 523 524<a name="filteringoutput"></a> 525 526<h3>Filtering Log Output</h3> 527 528<p>Every Android log message has a <em>tag</em> and a <em>priority</em> associated with it. </p> 529 530<ul> 531<li>The tag of a log message is a short string indicating the system component from which the message originates (for example, "View" for the view system). </li> 532 533<li>The priority is one of the following character values, ordered from lowest to highest priority:</li> 534 535<ul> 536 <li><code>V</code> — Verbose (lowest priority)</li> 537 <li><code>D</code> — Debug</li> 538 <li><code>I</code> — Info</li> 539 <li><code>W</code> — Warning</li> 540 <li><code>E</code> — Error</li> 541 <li><code>F</code> — Fatal</li> 542 <li><code>S</code> — Silent (highest priority, on which nothing is ever printed)</li> 543</ul> 544</ul> 545 546<p>You can obtain a list of tags used in the system, together with priorities, by running <code>logcat</code> and observing the first two columns 547of each message, given as <code><priority>/<tag></code>. </p> 548 549<p>Here's an example of logcat output that shows that the message relates to priority level "I" and tag "ActivityManager":</p> 550 551<pre>I/ActivityManager( 585): Starting activity: Intent { action=android.intent.action...}</pre> 552 553<p>To reduce the log output to a manageable level, you can restrict log output using <em>filter expressions</em>. Filter expressions let you indicate to the system the tags-priority combinations that you are interested in — the system suppresses other messages for the specified tags. </p> 554 555<p>A filter expression follows this format <code>tag:priority ...</code>, where <code>tag</code> indicates the tag of interest and <code>priority</code> indicates the <em>minimum</em> level of priority to report for that tag. Messages for that tag at or above the specified priority are written to the log. You can supply any number of <code>tag:priority</code> specifications in a single filter expression. The series of specifications is whitespace-delimited. </p> 556 557<p>Here's an example of a filter expression that suppresses all log messages except those with the tag "ActivityManager", at priority "Info" or above, and all log messages with tag "MyApp", with priority "Debug" or above:</p> 558 559<pre>adb logcat ActivityManager:I MyApp:D *:S</pre> 560 561<p>The final element in the above expression, <code>*:S</code>, sets the priority level for all tags to "silent", thus ensuring only log messages with "View" and "MyApp" are displayed. Using <code>*:S</code> is an excellent way to ensure that log output is restricted to the filters that you have explicitly specified — it lets your filters serve as a "whitelist" for log output.</p> 562 563<p>The following filter expression displays all log messages with priority level "warning" and higher, on all tags:</p> 564 565<pre>adb logcat *:W</pre> 566 567<p>If you're running <code>logcat</code> from your development computer (versus running it on a remote adb shell), you can also set a default filter expression by exporting a value for the environment variable <code>ANDROID_LOG_TAGS</code>:</p> 568 569<pre>export ANDROID_LOG_TAGS="ActivityManager:I MyApp:D *:S"</pre> 570 571<p>Note that <code>ANDROID_LOG_TAGS</code> filter is not exported to the emulator/device instance, if you are running <code>logcat</code> from a remote shell or using <code>adb shell logcat</code>.</p> 572 573 574<a name="outputformat"></a> 575 576<h3>Controlling Log Output Format</h3> 577 578<p>Log messages contain a number of metadata fields, in addition to the tag and priority. You can modify the output format for messages so that they display a specific metadata field. To do so, you use the <code>-v</code> option and specify one of the supported output formats listed below. </p> 579 580<ul> 581 <li><code>brief</code> — Display priority/tag and PID of originating process (the default format).</li> 582 <li><code>process</code> — Display PID only.</li> 583 <li><code>tag</code> — Display the priority/tag only. </li> 584 <li><code>thread</code> — Display process:thread and priority/tag only. </li> 585 <li><code>raw</code> — Display the raw log message, with no other metadata fields.</li> 586 <li><code>time</code> — Display the date, invocation time, priority/tag, and PID of the originating process.</li> 587 <li><code>long</code> — Display all metadata fields and separate messages with a blank lines.</li> 588</ul> 589 590<p>When starting <code>logcat</code>, you can specify the output format you want by using the <code>-v</code> option:</p> 591 592<pre>[adb] logcat [-v <format>]</pre> 593 594<p>Here's an example that shows how to generate messages in <code>thread</code> output format: </p> 595 596<pre>adb logcat -v thread</pre> 597 598<p>Note that you can only specify one output format with the <code>-v</code> option. </p> 599 600<a name="alternativebuffers"></a> 601 602<h3>Viewing Alternative Log Buffers </h3> 603 604<p>The Android logging system keeps multiple circular buffers for log messages, and not all of the log messages are sent to the default circular buffer. To see additional log messages, you can start <code>logcat</code> with the <code>-b</code> option, to request viewing of an alternate circular buffer. You can view any of these alternate buffers: </p> 605 606<ul> 607<li><code>radio</code> — View the buffer that contains radio/telephony related messages.</li> 608<li><code>events</code> — View the buffer containing events-related messages.</li> 609<li><code>main</code> — View the main log buffer (default)</li> 610</ul> 611 612<p>The usage of the <code>-b</code> option is:</p> 613 614<pre>[adb] logcat [-b <buffer>]</pre> 615 616<p>Here's an example of how to view a log buffer containing radio and telephony messages: </p> 617 618<pre>adb logcat -b radio</b></pre> 619 620<a name="stdout"></a> 621 622<h3>Viewing stdout and stderr</h3> 623 624<p>By default, the Android system sends <code>stdout</code> and <code>stderr</code> (<code>System.out</code> and <code>System.err</code>) output to <code>/dev/null</code>. In 625processes that run the Dalvik VM, you can have the system write a copy of the output to the log file. In this case, the system writes the messages to the log using the log tags <code>stdout</code> and <code>stderr</code>, both with priority <code>I</code>. </p> 626 627<p>To route the output in this way, you stop a running emulator/device instance and then use the shell command <code>setprop</code> to enable the redirection of output. Here's how you do it: </p> 628 629<pre>$ adb shell stop 630$ adb shell setprop log.redirect-stdio true 631$ adb shell start</pre> 632 633<p>The system retains this setting until you terminate the emulator/device instance. To use the setting as a default on the emulator/device instance, you can add an entry to <code>/data/local.prop</code> 634on the device.</p> 635 636<a name="logcatoptions"></a> 637 638<h3>Listing of logcat Command Options</h3> 639 640<table> 641<tr> 642 <th>Option</th> 643 <th>Description</th> 644</tr> 645 646<tr> 647<td><code>-b <buffer></code></td> 648<td>Loads an alternate log buffer for viewing, such as <code>event</code> or <code>radio</code>. The <code>main</code> buffer is used by default. See <a href="#alternativebuffers">Viewing Alternative Log Buffers</a>.</td> 649</tr> 650 651<tr> 652<td><code>-c</code></td> 653<td>Clears (flushes) the entire log and exits. </td> 654</tr> 655 656<tr> 657<td><code>-d</code></td> 658<td>Dumps the log to the screen and exits.</td> 659</tr> 660 661<tr> 662<td><code>-f <filename></code></td> 663<td>Writes log message output to <code><filename></code>. The default is <code>stdout</code>.</td> 664</tr> 665 666<tr> 667<td><code>-g</code></td> 668<td>Prints the size of the specified log buffer and exits. </td> 669</tr> 670 671<tr> 672<td><code>-n <count></code></td> 673<td>Sets the maximum number of rotated logs to <code><count></code>. The default value is 4. Requires the <code>-r</code> option. </td> 674</tr> 675 676<tr> 677<td><code>-r <kbytes></code></td> 678<td>Rotates the log file every <code><kbytes></code> of output. The default value is 16. Requires the <code>-f</code> option. </td> 679</tr> 680 681<tr> 682<td><code>-s</code></td> 683<td>Sets the default filter spec to silent. </td> 684</tr> 685 686<tr> 687<td><code>-v <format></code></td> 688<td>Sets the output format for log messages. The default is <code>brief</code> format. For a list of supported formats, see <a href="#outputformat">Controlling Log Output Format</a>.</td> 689</tr> 690 691</table> 692 693<a name="stopping"></a> 694 695<h2>Stopping the adb Server</h2> 696 697<p>In some cases, you might need to terminate the adb server process and then restart it. For example, if adb does not respond to a command, you can terminate the server and restart it and that may resolve the problem. </p> 698 699<p>To stop the adb server, use the <code>kill-server</code>. You can then restart the server by issuing any adb command. </p> 700 701 702