path: root/lib/stdlib/doc/src/c.xml

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  <header>
    <copyright>
      <year>1996</year><year>2009</year>
      <holder>Ericsson AB. All Rights Reserved.</holder>
    </copyright>
    <legalnotice>
      The contents of this file are subject to the Erlang Public License,
      Version 1.1, (the "License"); you may not use this file except in
      compliance with the License. You should have received a copy of the
      Erlang Public License along with this software. If not, it can be
      retrieved online at http://www.erlang.org/.
    
      Software distributed under the License is distributed on an "AS IS"
      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
      the License for the specific language governing rights and limitations
      under the License.
    
    </legalnotice>

    <title>c</title>
    <prepared>Joe Armstrong</prepared>
    <docno>1</docno>
    <date>96-10-30</date>
    <rev>B</rev>
  </header>
  <module>c</module>
  <modulesummary>Command Interface Module</modulesummary>
  <description>
    <p>The <c>c</c> module enables users to enter the short form of
      some commonly used commands.</p>
    <note>
      <p>These functions are are intended for interactive use in
        the Erlang shell only. The module prefix may be omitted.</p>
    </note>
  </description>
  <funcs>
    <func>
      <name>bt(Pid) -> void()</name>
      <fsummary>Stack backtrace for a process</fsummary>
      <type>
        <v>Pid = pid()</v>
      </type>
      <desc>
        <p>Stack backtrace for a process. Equivalent to
          <c>erlang:process_display(Pid, backtrace)</c>.</p>
      </desc>
    </func>
    <func>
      <name>c(File) -> {ok, Module} | error</name>
      <name>c(File, Options) -> {ok, Module} | error</name>
      <fsummary>Compile and load code in a file</fsummary>
      <type>
        <v>File = name() -- see filename(3)</v>
        <v>Options = [Opt] -- see compile:file/2</v>
      </type>
      <desc>
        <p><c>c/1,2</c> compiles and then purges and loads the code for
          a file. <c>Options</c> defaults to []. Compilation is
          equivalent to:</p>
        <code type="none">
compile:file(File, Options ++ [report_errors, report_warnings])</code>
        <p>Note that purging the code means that any processes
          lingering in old code for the module are killed without
          warning. See <c>code/3</c> for more information.</p>
      </desc>
    </func>
    <func>
      <name>cd(Dir) -> void()</name>
      <fsummary>Change working directory</fsummary>
      <type>
        <v>Dir = name() -- see filename(3)</v>
      </type>
      <desc>
        <p>Changes working directory to <c>Dir</c>, which may be a
          relative name, and then prints the name of the new working
          directory.</p>
        <pre>
2> <input>cd("../erlang").</input>
/home/ron/erlang</pre>
      </desc>
    </func>
    <func>
      <name>flush() -> void()</name>
      <fsummary>Flush any messages sent to the shell</fsummary>
      <desc>
        <p>Flushes any messages sent to the shell.</p>
      </desc>
    </func>
    <func>
      <name>help() -> void()</name>
      <fsummary>Help information</fsummary>
      <desc>
        <p>Displays help information: all valid shell internal commands,
          and commands in this module.</p>
      </desc>
    </func>
    <func>
      <name>i() -> void()</name>
      <name>ni() -> void()</name>
      <fsummary>Information about the system</fsummary>
      <desc>
        <p><c>i/0</c> displays information about the system, listing
          information about all processes. <c>ni/0</c> does the same,
          but for all nodes the network.</p>
      </desc>
    </func>
    <func>
      <name>i(X, Y, Z) -> void()</name>
      <fsummary>Information about pid &lt;X.Y.Z&gt;</fsummary>
      <type>
        <v>X = Y = Z = int()</v>
      </type>
      <desc>
        <p>Displays information about a process, Equivalent to
          <c>process_info(pid(X, Y, Z))</c>, but location transparent.</p>
      </desc>
    </func>
    <func>
      <name>l(Module) -> void()</name>
      <fsummary>Load or reload module</fsummary>
      <type>
        <v>Module = atom()</v>
      </type>
      <desc>
        <p>Purges and loads, or reloads, a module by calling
          <c>code:purge(Module)</c> followed by
          <c>code:load_file(Module)</c>.</p>
        <p>Note that purging the code means that any processes
          lingering in old code for the module are killed without
          warning. See <c>code/3</c> for more information.</p>
      </desc>
    </func>
    <func>
      <name>lc(Files) -> ok</name>
      <fsummary>Compile a list of files</fsummary>
      <type>
        <v>Files = [File]</v>
        <v>&nbsp;File = name() -- see filename(3)</v>
      </type>
      <desc>
        <p>Compiles a list of files by calling <c>compile:file(File, [report_errors, report_warnings])</c> for each <c>File</c>
          in <c>Files</c>.</p>
      </desc>
    </func>
    <func>
      <name>ls() -> void()</name>
      <fsummary>List files in the current directory</fsummary>
      <desc>
        <p>Lists files in the current directory.</p>
      </desc>
    </func>
    <func>
      <name>ls(Dir) -> void()</name>
      <fsummary>List files in a directory</fsummary>
      <type>
        <v>Dir = name() -- see filename(3)</v>
      </type>
      <desc>
        <p>Lists files in directory <c>Dir</c>.</p>
      </desc>
    </func>
    <func>
      <name>m() -> void()</name>
      <fsummary>Which modules are loaded</fsummary>
      <desc>
        <p>Displays information about the loaded modules, including
          the files from which they have been loaded.</p>
      </desc>
    </func>
    <func>
      <name>m(Module) -> void()</name>
      <fsummary>Information about a module</fsummary>
      <type>
        <v>Module = atom()</v>
      </type>
      <desc>
        <p>Displays information about <c>Module</c>.</p>
      </desc>
    </func>
    <func>
      <name>memory() -> [{Type, Size}]</name>
      <fsummary>Memory allocation information</fsummary>
      <type>
        <v>Type, Size -- see erlang:memory/0</v>
      </type>
      <desc>
        <p>Memory allocation information. Equivalent to
          <c>erlang:memory/0</c>.</p>
      </desc>
    </func>
    <func>
      <name>memory(Type) -> Size</name>
      <name>memory([Type]) -> [{Type, Size}]</name>
      <fsummary>Memory allocation information</fsummary>
      <type>
        <v>Type, Size -- see erlang:memory/0</v>
      </type>
      <desc>
        <p>Memory allocation information. Equivalent to
          <c>erlang:memory/1</c>.</p>
      </desc>
    </func>
    <func>
      <name>nc(File) -> {ok, Module} | error</name>
      <name>nc(File, Options) -> {ok, Module} | error</name>
      <fsummary>Compile and load code in a file on all nodes</fsummary>
      <type>
        <v>File = name() -- see filename(3)</v>
        <v>Options = [Opt] -- see compile:file/2</v>
      </type>
      <desc>
        <p>Compiles and then loads the code for a file on all nodes.
          <c>Options</c> defaults to []. Compilation is equivalent to:</p>
        <code type="none">
compile:file(File, Opts ++ [report_errors, report_warnings])</code>
      </desc>
    </func>
    <func>
      <name>nl(Module) -> void()</name>
      <fsummary>Load module on all nodes</fsummary>
      <type>
        <v>Module = atom()</v>
      </type>
      <desc>
        <p>Loads <c>Module</c> on all nodes.</p>
      </desc>
    </func>
    <func>
      <name>pid(X, Y, Z) -> pid()</name>
      <fsummary>Convert X,Y,Z to a pid</fsummary>
      <type>
        <v>X = Y = Z = int()</v>
      </type>
      <desc>
        <p>Converts <c>X</c>, <c>Y</c>, <c>Z</c> to the pid
          <c><![CDATA[<X.Y.Z>]]></c>. This function should only be used when
          debugging.</p>
      </desc>
    </func>
    <func>
      <name>pwd() -> void()</name>
      <fsummary>Print working directory</fsummary>
      <desc>
        <p>Prints the name of the working directory.</p>
      </desc>
    </func>
    <func>
      <name>q() -> void()</name>
      <fsummary>Quit - shorthand for <c>init:stop()</c></fsummary>
      <desc>
        <p>This function is shorthand for <c>init:stop()</c>, that is,
          it causes the node to stop in a controlled fashion.</p>
      </desc>
    </func>
    <func>
      <name>regs() -> void()</name>
      <name>nregs() -> void()</name>
      <fsummary>Information about registered processes</fsummary>
      <desc>
        <p><c>regs/0</c> displays information about all registered
          processes. <c>nregs/0</c> does the same, but for all nodes
          in the network.</p>
      </desc>
    </func>
    <func>
      <name>xm(ModSpec) -> void()</name>
      <fsummary>Cross reference check a module</fsummary>
      <type>
        <v>ModSpec = Module | Filename</v>
        <v>&nbsp;Module = atom()</v>
        <v>&nbsp;Filename = string()</v>
      </type>
      <desc>
        <p>This function finds undefined functions, unused functions,
          and calls to deprecated functions in a module by calling
          <c>xref:m/1</c>.</p>
      </desc>
    </func>
    <func>
      <name>y(File) -> YeccRet</name>
      <fsummary>Generate an LALR-1 parser</fsummary>
      <type>
        <v>File = name() -- see filename(3)</v>
        <v>YeccRet = -- see yecc:file/2</v>
      </type>
      <desc>
        <p>Generates an LALR-1 parser. Equivalent to:</p>
        <code type="none">
yecc:file(File)</code>
      </desc>
    </func>
    <func>
      <name>y(File, Options) -> YeccRet</name>
      <fsummary>Generate an LALR-1 parser</fsummary>
      <type>
        <v>File = name() -- see filename(3)</v>
        <v>Options, YeccRet = -- see yecc:file/2</v>
      </type>
      <desc>
        <p>Generates an LALR-1 parser. Equivalent to:</p>
        <code type="none">
yecc:file(File, Options)</code>
      </desc>
    </func>
  </funcs>

  <section>
    <title>See Also</title>
    <p><seealso marker="compiler:compile">compile(3)</seealso>,
      <seealso marker="filename">filename(3)</seealso>, 
      <seealso marker="erts:erlang">erlang(3)</seealso>, 
      <seealso marker="parsetools:yecc">yecc(3)</seealso>,
      <seealso marker="tools:xref">xref(3)</seealso></p>
  </section>
</erlref>