.TH erlc 1 "erts  5.6.3" "Ericsson AB" "USER COMMANDS"
.SH NAME
erlc \- Compiler
.SH DESCRIPTION
.LP
The \fIerlc\fR program provides a common way to run all compilers in the Erlang system\&. Depending on the extension of each input file, \fIerlc\fR will invoke the appropriate compiler\&. Regardless of which compiler is used, the same flags are used to provide parameters such as include paths and output directory\&.
.LP


.SH EXPORTS
.LP
.B
erlc flags file1\&.ext file2\&.ext\&.\&.\&.
.br
.RS
.LP
\fIErlc\fR compiles one or more files\&. The files must include the extension, for example \fI\&.erl\fR for Erlang source code, or \fI\&.yrl\fR for Yecc source code\&. \fIErlc\fR uses the extension to invoke the correct compiler\&.
.RE
.SH GENERALLY USEFUL FLAGS
.LP
The following flags are supported: 
.RS 2
.TP 4
.B
-I \fIdirectory\fR:
Instructs the compiler to search for include files in the specified directory\&. When encountering an \fI-include\fR or \fI-include_dir\fR directive, the compiler searches for header files in the following directories:
.RS 4
.LP

.RS 2
.TP 4
1.
\fI"\&."\fR, the current working directory of the file server;
.TP 4
2.
the base name of the compiled file;
.TP 4
3.
the directories specified using the \fI-I\fR option\&. The directory specified last is searched first\&.
.RE
.RE
.TP 4
.B
-o \fIdirectory\fR:
The directory where the compiler should place the output files\&. If not specified, output files will be placed in the current working directory\&.
.TP 4
.B
-D\fIname\fR:
Defines a macro\&.
.TP 4
.B
-D\fIname\fR=\fIvalue\fR:
Defines a macro with the given value\&. The value can be any Erlang term\&. Depending on the platform, the value may need to be quoted if the shell itself interprets certain characters\&. On Unix, terms which contain tuples and list must be quoted\&. Terms which contain spaces must be quoted on all platforms\&.
.TP 4
.B
-W\fInumber\fR:
Sets warning level to \fInumber\fR\&. Default is \fI1\fR\&. Use \fI-W0\fR to turn off warnings\&.
.TP 4
.B
-W:
Same as \fI-W1\fR\&. Default\&.
.TP 4
.B
-v:
Enables verbose output\&.
.TP 4
.B
-b \fIoutput-type\fR:
Specifies the type of output file\&. Generally, \fIoutput-type\fR is the same as the file extension of the output file but without the period\&. This option will be ignored by compilers that have a a single output format\&.
.TP 4
.B
-hybrid:
Compile using the hybrid-heap emulator\&. This is mainly useful for compiling native code, which needs to be compiled with the same run-time system that it should be run on\&.
.TP 4
.B
-smp:
Compile using the SMP emulator\&. This is mainly useful for compiling native code, which needs to be compiled with the same run-time system that it should be run on\&.
.TP 4
.B
--:
Signals that no more options will follow\&. The rest of the arguments will be treated as file names, even if they start with hyphens\&.
.TP 4
.B
+\fIterm\fR:
A flag starting with a plus (\&'\fI+\fR\&') rather than a hyphen will be converted to an Erlang term and passed unchanged to the compiler\&. For instance, the \fIexport_all\fR option for the Erlang compiler can be specified as follows:
.RS 4
.LP


.nf
erlc +export_all file\&.erl
.fi
.LP

.LP
Depending on the platform, the value may need to be quoted if the shell itself interprets certain characters\&. On Unix, terms which contain tuples and list must be quoted\&. Terms which contain spaces must be quoted on all platforms\&.
.RE
.RE
.SH SPECIAL FLAGS
.LP
The flags in this section are useful in special situations such as re-building the OTP system\&.
.RS 2
.TP 4
.B
-pa \fIdirectory\fR:
Appends \fIdirectory\fR to the front of the code path in the invoked Erlang emulator\&. This can be used to invoke another compiler than the default one\&.
.TP 4
.B
-pz \fIdirectory\fR:
Appends \fIdirectory\fR to the code path in the invoked Erlang emulator\&.
.RE
.SH SUPPORTED COMPILERS
.RS 2
.TP 4
.B
\&.erl:
Erlang source code\&. It generates a \fI\&.beam\fR file\&.
.RS 4
.LP

.LP
The options -P, -E, and -S are equivalent to +\&'P\&', +\&'E\&', and +\&'S\&', except that it is not necessary to include the single quotes to protect them from the shell\&.
.LP

.LP
Supported options: -I, -o, -D, -v, -W, -b\&.
.RE
.TP 4
.B
\&.yrl:
Yecc source code\&. It generates an \fI\&.erl\fR file\&.
.RS 4
.LP

.LP
Use the -I option with the name of a file to use that file as a customized prologue file (the \fIincludefile\fR option)\&.
.LP

.LP
Supported options: -o, -v, -I, -W (see above)\&.
.RE
.TP 4
.B
\&.mib:
MIB for SNMP\&. It generates a \fI\&.bin\fR file\&.
.RS 4
.LP

.LP
Supported options: -I, -o, -W\&.
.RE
.TP 4
.B
\&.bin:
A compiled MIB for SNMP\&. It generates a \fI\&.hrl\fR file\&.
.RS 4
.LP

.LP
Supported options: -o, -v\&.
.RE
.TP 4
.B
\&.rel:
Script file\&. It generates a boot file\&.
.RS 4
.LP

.LP
Use the -I to name directories to be searched for application files (equivalent to the \fIpath\fR in the option list for \fIsystools:make_script/2\fR)\&.
.LP

.LP
Supported options: -o\&.
.RE
.TP 4
.B
\&.asn1:
ASN1 file\&.
.RS 4
.LP

.LP
Creates an \fI\&.erl\fR, \fI\&.hrl\fR, and \fI\&.asn1db\fR file from an \fI\&.asn1\fR file\&. Also compiles the \fI\&.erl\fR using the Erlang compiler unless the \fI+noobj\fR options is given\&.
.LP

.LP
Supported options: -I, -o, -b, -W\&.
.RE
.TP 4
.B
\&.idl:
IC file\&.
.RS 4
.LP

.LP
Runs the IDL compiler\&.
.LP

.LP
Supported options: -I, -o\&.
.RE
.RE
.SH ENVIRONMENT VARIABLES
.RS 2
.TP 4
.B
ERLC_EMULATOR:
The command for starting the emulator\&. Default is \fIerl\fR in the same directory as the \fIerlc\fR program itself, or if it doesn\&'t exist, \fIerl\fR in any of the directories given in the \fIPATH\fR environment variable\&.
.RE
.SH SEE ALSO
.LP
erl(1), compile(3), yecc(3), snmp(3)