NAME

       ecpg - embedded SQL C preprocessor

SYNOPSIS

       ecpg [option...] file...

DESCRIPTION

       ecpg is the embedded SQL preprocessor for C programs. It converts C programs with embedded
       SQL statements to normal C code by replacing the SQL invocations with special function
       calls. The output files can then be processed with any C compiler tool chain.

       ecpg will convert each input file given on the command line to the corresponding C output
       file. If an input file name does not have any extension, .pgc is assumed. The file's
       extension will be replaced by .c to construct the output file name. But the output file
       name can be overridden using the -o option.

       If an input file name is just -, ecpg reads the program from standard input (and writes to
       standard output, unless that is overridden with -o).

       This reference page does not describe the embedded SQL language. See Chapter 36 for more
       information on that topic.

OPTIONS

       ecpg accepts the following command-line arguments:

       -c
           Automatically generate certain C code from SQL code. Currently, this works for EXEC
           SQL TYPE.

       -C mode
           Set a compatibility mode.  mode can be INFORMIX, INFORMIX_SE, or ORACLE.

       -D symbol[=value]
           Define a preprocessor symbol, equivalently to the EXEC SQL DEFINE directive. If no
           value is specified, the symbol is defined with the value 1.

       -h
           Process header files. When this option is specified, the output file extension becomes
           .h not .c, and the default input file extension is .pgh not .pgc. Also, the -c option
           is forced on.

       -i
           Parse system include files as well.

       -I directory
           Specify an additional include path, used to find files included via EXEC SQL INCLUDE.
           Defaults are .  (current directory), /usr/local/include, the PostgreSQL include
           directory which is defined at compile time (default: /usr/local/pgsql/include), and
           /usr/include, in that order.

       -o filename
           Specifies that ecpg should write all its output to the given filename. Write -o - to
           send all output to standard output.

       -r option
           Selects run-time behavior.  Option can be one of the following:

           no_indicator
               Do not use indicators but instead use special values to represent null values.
               Historically there have been databases using this approach.

           prepare
               Prepare all statements before using them. Libecpg will keep a cache of prepared
               statements and reuse a statement if it gets executed again. If the cache runs
               full, libecpg will free the least used statement.

           questionmarks
               Allow question mark as placeholder for compatibility reasons. This used to be the
               default long ago.

       -t
           Turn on autocommit of transactions. In this mode, each SQL command is automatically
           committed unless it is inside an explicit transaction block. In the default mode,
           commands are committed only when EXEC SQL COMMIT is issued.

       -v
           Print additional information including the version and the "include" path.

       --version
           Print the ecpg version and exit.

       -?
       --help
           Show help about ecpg command line arguments, and exit.

NOTES

       When compiling the preprocessed C code files, the compiler needs to be able to find the
       ECPG header files in the PostgreSQL include directory. Therefore, you might have to use
       the -I option when invoking the compiler (e.g., -I/usr/local/pgsql/include).

       Programs using C code with embedded SQL have to be linked against the libecpg library, for
       example using the linker options -L/usr/local/pgsql/lib -lecpg.

       The value of either of these directories that is appropriate for the installation can be
       found out using pg_config(1).

EXAMPLES

       If you have an embedded SQL C source file named prog1.pgc, you can create an executable
       program using the following sequence of commands:

           ecpg prog1.pgc
           cc -I/usr/local/pgsql/include -c prog1.c
           cc -o prog1 prog1.o -L/usr/local/pgsql/lib -lecpg