.TH c 3erl "stdlib 5.2" "Ericsson AB" "Erlang Module Definition"
.SH NAME
c \- Command interface module.
.SH DESCRIPTION
.LP
This module enables users to enter the short form of some commonly used commands\&.
.LP

.RS -4
.B
Note:
.RE
These functions are intended for interactive use in the Erlang shell only\&. The module prefix can be omitted\&.

.SH EXPORTS
.LP
.nf

.B
bt(Pid) -> ok | undefined
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Pid = pid()
.br
.RE
.RE
.RS
.LP
Stack backtrace for a process\&. Equivalent to \fIerlang:process_display(Pid, backtrace)\fR\&\&.
.RE

.LP
.nf

.B
c(Module) -> {ok, ModuleName} | error
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Module = file:name()
.br
ModuleName = module()
.br
.RE
.RE
.RS
.LP
Works like \fIc(Module, [])\fR\&\&.
.RE

.LP
.nf

.B
c(Module, Options) -> {ok, ModuleName} | error
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Module = file:name()
.br
Options = [compile:option()] | compile:option()
.br
ModuleName = module()
.br
.RE
.RE
.RS
.LP
Compiles and then purges and loads the code for a module\&. \fIModule\fR\& can be either a module name or a source file path, with or without \fI\&.erl\fR\& extension\&.
.LP
If \fIModule\fR\& is a string, it is assumed to be a source file path, and the compiler will attempt to compile the source file with the options \fIOptions\fR\&\&. If compilation fails, the old object file (if any) is deleted\&.
.LP
If \fIModule\fR\& is an atom, a source file with that exact name or with \fI\&.erl\fR\& extension will be looked for\&. If found, the source file is compiled with the options \fIOptions\fR\&\&. If compilation fails, the old object file (if any) is deleted\&.
.LP
If \fIModule\fR\& is an atom and is not the path of a source file, then the code path is searched to locate the object file for the module and extract its original compiler options and source path\&. If the source file is not found in the original location, \fIfilelib:find_source/1\fR\& is used to search for it relative to the directory of the object file\&.
.LP
The source file is compiled with the the original options appended to the given \fIOptions\fR\&, the output replacing the old object file if and only if compilation succeeds\&.
.LP
Notice that purging the code means that any processes lingering in old code for the module are killed without warning\&. For more information, see the code module\&.
.RE

.LP
.nf

.B
c(Module, Options, Filter) -> {ok, ModuleName} | error
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Module = atom()
.br
Options = [compile:option()]
.br
Filter = fun((compile:option()) -> boolean())
.br
ModuleName = module()
.br
.RE
.RE
.RS
.LP
Compiles and then purges and loads the code for module \fIModule\fR\&, which must be an atom\&.
.LP
The code path is searched to locate the object file for module \fIModule\fR\& and extract its original compiler options and source path\&. If the source file is not found in the original location, \fIfilelib:find_source/1\fR\& is used to search for it relative to the directory of the object file\&.
.LP
The source file is compiled with the the original options appended to the given \fIOptions\fR\&, the output replacing the old object file if and only if compilation succeeds\&. The function \fIFilter\fR\& specifies which elements to remove from the original compiler options before the new options are added\&. The \fIFilter\fR\& fun should return \fItrue\fR\& for options to keep, and \fIfalse\fR\& for options to remove\&.
.LP
Notice that purging the code means that any processes lingering in old code for the module are killed without warning\&. For more information, see the code module\&.
.RE

.LP
.nf

.B
cd(Dir) -> ok
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Dir = file:name()
.br
.RE
.RE
.RS
.LP
Changes working directory to \fIDir\fR\&, which can be a relative name, and then prints the name of the new working directory\&.
.LP
\fIExample:\fR\&
.LP
.nf

2> cd("\&.\&./erlang")\&.
/home/ron/erlang
.fi
.RE

.LP
.nf

.B
erlangrc(PathList) -> {ok, file:filename()} | {error, term()}
.br
.fi
.br
.RS
.LP
Types:

.RS 3
PathList = [Dir :: file:name()]
.br
.RE
.RE
.RS
.LP
Search \fIPathList\fR\& and load \fI\&.erlang\fR\& resource file if found\&.
.RE

.LP
.nf

.B
flush() -> ok
.br
.fi
.br
.RS
.LP
Flushes any messages sent to the shell\&.
.RE

.LP
.nf

.B
help() -> ok
.br
.fi
.br
.RS
.LP
Displays help information: all valid shell internal commands, and commands in this module\&.
.RE

.LP
.nf

.B
h(Module :: module()) -> h_return()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
.nf
\fBh_return()\fR\& = 
.br
    ok | {error, missing | {unknown_format, unicode:chardata()}}
.fi
.br
.RE
.RE
.RS
.LP
Print the documentation for \fIModule\fR\&
.RE

.LP
.nf

.B
h(Module :: module(), Function :: function()) -> hf_return()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
.nf
\fBh_return()\fR\& = 
.br
    ok | {error, missing | {unknown_format, unicode:chardata()}}
.fi
.br
.nf
\fBhf_return()\fR\& = h_return() | {error, function_missing}
.fi
.br
.RE
.RE
.RS
.LP
Print the documentation for all \fIModule:Function\fR\&s (regardless of arity)\&.
.RE

.LP
.nf

.B
h(Module :: module(), Function :: function(), Arity :: arity()) ->
.B
     hf_return()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
.nf
\fBh_return()\fR\& = 
.br
    ok | {error, missing | {unknown_format, unicode:chardata()}}
.fi
.br
.nf
\fBhf_return()\fR\& = h_return() | {error, function_missing}
.fi
.br
.RE
.RE
.RS
.LP
Print the documentation for \fIModule:Function/Arity\fR\&\&.
.RE

.LP
.nf

.B
hcb(Module :: module()) -> h_return()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
.nf
\fBh_return()\fR\& = 
.br
    ok | {error, missing | {unknown_format, unicode:chardata()}}
.fi
.br
.RE
.RE
.RS
.LP
Print the callback documentation for \fIModule\fR\&
.RE

.LP
.nf

.B
hcb(Module :: module(), Callback :: atom()) -> hcb_return()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
.nf
\fBh_return()\fR\& = 
.br
    ok | {error, missing | {unknown_format, unicode:chardata()}}
.fi
.br
.nf
\fBhcb_return()\fR\& = h_return() | {error, callback_missing}
.fi
.br
.RE
.RE
.RS
.LP
Print the callback documentation for all \fIModule:Callback\fR\&s (regardless of arity)\&.
.RE

.LP
.nf

.B
hcb(Module :: module(), Callback :: atom(), Arity :: arity()) ->
.B
       hcb_return()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
.nf
\fBh_return()\fR\& = 
.br
    ok | {error, missing | {unknown_format, unicode:chardata()}}
.fi
.br
.nf
\fBhcb_return()\fR\& = h_return() | {error, callback_missing}
.fi
.br
.RE
.RE
.RS
.LP
Print the callback documentation for \fIModule:Callback/Arity\fR\&\&.
.RE

.LP
.nf

.B
ht(Module :: module()) -> h_return()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
.nf
\fBh_return()\fR\& = 
.br
    ok | {error, missing | {unknown_format, unicode:chardata()}}
.fi
.br
.RE
.RE
.RS
.LP
Print the type documentation for \fIModule\fR\&
.RE

.LP
.nf

.B
ht(Module :: module(), Type :: atom()) -> ht_return()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
.nf
\fBh_return()\fR\& = 
.br
    ok | {error, missing | {unknown_format, unicode:chardata()}}
.fi
.br
.nf
\fBht_return()\fR\& = h_return() | {error, type_missing}
.fi
.br
.RE
.RE
.RS
.LP
Print the type documentation for \fIType\fR\& in \fIModule\fR\& regardless of arity\&.
.RE

.LP
.nf

.B
ht(Module :: module(), Type :: atom(), Arity :: arity()) ->
.B
      ht_return()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
.nf
\fBh_return()\fR\& = 
.br
    ok | {error, missing | {unknown_format, unicode:chardata()}}
.fi
.br
.nf
\fBht_return()\fR\& = h_return() | {error, type_missing}
.fi
.br
.RE
.RE
.RS
.LP
Print the type documentation for \fIType/Arity\fR\& in \fIModule\fR\&\&.
.RE

.LP
.nf

.B
i() -> ok
.br
.fi
.br
.nf

.B
ni() -> ok
.br
.fi
.br
.RS
.LP
\fIi/0\fR\& displays system information, listing information about all processes\&. \fIni/0\fR\& does the same, but for all nodes in the network\&.
.RE

.LP
.nf

.B
i(X, Y, Z) -> [{atom(), term()}]
.br
.fi
.br
.RS
.LP
Types:

.RS 3
X = Y = Z = integer() >= 0
.br
.RE
.RE
.RS
.LP
Displays information about a process, Equivalent to \fIprocess_info(pid(X, Y, Z))\fR\&, but location transparent\&.
.RE

.LP
.nf

.B
l(Module) -> code:load_ret()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Module = module()
.br
.RE
.RE
.RS
.LP
Purges and loads, or reloads, a module by calling \fIcode:purge(Module)\fR\& followed by \fIcode:load_file(Module)\fR\&\&.
.LP
Notice that purging the code means that any processes lingering in old code for the module are killed without warning\&. For more information, see \fIcode/3\fR\&\&.
.RE

.LP
.B
lc(Files) -> ok
.br
.RS
.LP
Types:

.RS 3
Files = [File]
.br
File
.br
.RE
.RE
.RS
.LP
Compiles a list of files by calling \fIcompile:file(File, [report_errors, report_warnings])\fR\& for each \fIFile\fR\& in \fIFiles\fR\&\&.
.LP
For information about \fIFile\fR\&, see \fIfile:filename()\fR\&\&.
.RE

.LP
.nf

.B
lm() -> [code:load_ret()]
.br
.fi
.br
.RS
.LP
Reloads all currently loaded modules that have changed on disk (see \fImm()\fR\&)\&. Returns the list of results from calling \fIl(M)\fR\& for each such \fIM\fR\&\&.
.RE

.LP
.nf

.B
ls() -> ok
.br
.fi
.br
.RS
.LP
Lists files in the current directory\&.
.RE

.LP
.nf

.B
ls(Dir) -> ok
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Dir = file:name()
.br
.RE
.RE
.RS
.LP
Lists files in directory \fIDir\fR\& or, if \fIDir\fR\& is a file, only lists it\&.
.RE

.LP
.nf

.B
m() -> ok
.br
.fi
.br
.RS
.LP
Displays information about the loaded modules, including the files from which they have been loaded\&.
.RE

.LP
.nf

.B
m(Module) -> ok
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Module = module()
.br
.RE
.RE
.RS
.LP
Displays information about \fIModule\fR\&\&.
.RE

.LP
.nf

.B
mm() -> [module()]
.br
.fi
.br
.RS
.LP
Lists all modified modules\&. Shorthand for \fIcode:modified_modules/0\fR\&\&.
.RE

.LP
.nf

.B
memory() -> [{Type, Size}]
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Type = atom()
.br
Size = integer() >= 0
.br
.RE
.RE
.RS
.LP
Memory allocation information\&. Equivalent to \fIerlang:memory/0\fR\&\&.
.RE

.LP
.nf

.B
memory(Type) -> Size
.br
.fi
.br
.nf

.B
memory(Types) -> [{Type, Size}]
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Types = [Type]
.br
Type = atom()
.br
Size = integer() >= 0
.br
.RE
.RE
.RS
.LP
Memory allocation information\&. Equivalent to \fIerlang:memory/1\fR\&\&.
.RE

.LP
.nf

.B
nc(File) -> {ok, Module} | error
.br
.fi
.br
.nf

.B
nc(File, Options) -> {ok, Module} | error
.br
.fi
.br
.RS
.LP
Types:

.RS 3
File = file:name()
.br
Options = [Option] | Option
.br
Option = compile:option()
.br
Module = module()
.br
.RE
.RE
.RS
.LP
Compiles and then loads the code for a file on all nodes\&. \fIOptions\fR\& defaults to \fI[]\fR\&\&. Compilation is equivalent to:
.LP
.nf

compile:file(File, Options ++ [report_errors, report_warnings])
.fi
.RE

.LP
.nf

.B
nl(Module) -> abcast | error
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Module = module()
.br
.RE
.RE
.RS
.LP
Loads \fIModule\fR\& on all nodes\&.
.RE

.LP
.nf

.B
pid(X, Y, Z) -> pid()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
X = Y = Z = integer() >= 0
.br
.RE
.RE
.RS
.LP
Converts \fIX\fR\&, \fIY\fR\&, \fIZ\fR\& to pid \fI<X\&.Y\&.Z>\fR\&\&. This function is only to be used when debugging\&.
.RE

.LP
.nf

.B
pwd() -> ok
.br
.fi
.br
.RS
.LP
Prints the name of the working directory\&.
.RE

.LP
.nf

.B
q() -> no_return()
.br
.fi
.br
.RS
.LP
This function is shorthand for \fIinit:stop()\fR\&, that is, it causes the node to stop in a controlled fashion\&.
.RE

.LP
.nf

.B
regs() -> ok
.br
.fi
.br
.nf

.B
nregs() -> ok
.br
.fi
.br
.RS
.LP
\fIregs/0\fR\& displays information about all registered processes\&. \fInregs/0\fR\& does the same, but for all nodes in the network\&.
.RE

.LP
.nf

.B
uptime() -> ok
.br
.fi
.br
.RS
.LP
Prints the node uptime (as specified by \fIerlang:statistics(wall_clock)\fR\&) in human-readable form\&.
.RE

.LP
.B
xm(ModSpec) -> void()
.br
.RS
.LP
Types:

.RS 3
ModSpec = Module | Filename
.br
 Module = atom()
.br
 Filename = string()
.br
.RE
.RE
.RS
.LP
Finds undefined functions, unused functions, and calls to deprecated functions in a module by calling \fIxref:m/1\fR\&\&.
.RE

.LP
.B
y(File) -> YeccRet
.br
.RS
.LP
Types:

.RS 3
File = name()
.br
YeccRet
.br
.RE
.RE
.RS
.LP
Generates an LALR-1 parser\&. Equivalent to:
.LP
.nf

yecc:file(File)
.fi
.LP
For information about \fIFile = name()\fR\&, see \fIfilename(3erl)\fR\&\&. For information about \fIYeccRet\fR\&, see \fIyecc:file/2\fR\&\&.
.RE

.LP
.B
y(File, Options) -> YeccRet
.br
.RS
.LP
Types:

.RS 3
File = name()
.br
Options, YeccRet
.br
.RE
.RE
.RS
.LP
Generates an LALR-1 parser\&. Equivalent to:
.LP
.nf

yecc:file(File, Options)
.fi
.LP
For information about \fIFile = name()\fR\&, see \fIfilename(3erl)\fR\&\&. For information about \fIOptions\fR\& and \fIYeccRet\fR\&, see \fIyecc:file/2\fR\&\&.
.RE

.SH "SEE ALSO"

.LP
\fIfilename(3erl)\fR\&, \fIcompile(3erl)\fR\&, \fIerlang(3erl)\fR\&, \fIyecc(3erl)\fR\&, \fIxref(3erl)\fR\&