Section: POSIX Programmer's Manual (1P)
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
--- generate a formatted message catalog
gencat catfile msgfile...
utility shall merge the message text source file
into a formatted message catalog
shall be created if it does not already exist. If
does exist, its messages shall be included in the new
If set and message numbers collide, the new message text defined in
shall replace the old message text currently contained in
The following operands shall be supported:
A pathname of the formatted message catalog. If
is specified, standard output shall be used. The format of the message
catalog produced is unspecified.
A pathname of a message text source file. If
is specified for an instance of
standard input shall be used. The format of message text source files
is defined in the EXTENDED DESCRIPTION section.
The standard input shall not be used unless a
operand is specified as
The input files shall be text files.
The following environment variables shall affect the execution of
Provide a default value for the internationalization variables that are
unset or null. (See the Base Definitions volume of POSIX.1-2017,
Section 8.2, Internationalization Variables
for the precedence of internationalization variables used to determine
the values of locale categories.)
If set to a non-empty string value, override the values of all the
other internationalization variables.
Determine the locale for the interpretation of sequences of bytes of
text data as characters (for example, single-byte as opposed to
multi-byte characters in arguments and input files).
Determine the locale that should be used to affect the format and
contents of diagnostic messages written to standard error.
Determine the location of message catalogs for the processing of
The standard output shall not be used unless the
operand is specified as
The standard error shall be used only for diagnostic messages.
The content of a message text file shall be in the format defined as
follows. Note that the fields of a message text source line are
separated by a single
character. Any other
characters are considered to be part of the subsequent field.
- $set n comment
This line specifies the set identifier of the following messages until
or end-of-file appears. The
denotes the set identifier, which is defined as a number in the range
header defined in the Base Definitions volume of POSIX.1-2017). The application shall ensure that set
identifiers are presented in ascending order within a single source
file, but need not be contiguous. Any string following the set
identifier shall be treated as a comment. If no
directive is specified in a message text source file, all messages
shall be located in an implementation-defined default message set
NL_SETD (see the
header defined in the Base Definitions volume of POSIX.1-2017).
- $delset n comment
This line deletes message set
from an existing message catalog. The
denotes the set number [1,
Any string following the set number shall be treated as a comment.
- $ comment
A line beginning with
followed by a
shall be treated as a comment.
- m message-text
denotes the message identifier, which is defined as a number in the
shall be stored in the message catalog with the set identifier
specified by the last
directive, and with message identifier
is empty, and a
field separator is present, an empty string shall be stored
in the message catalog. If a message source line has a message number,
but neither a field separator nor
the existing message with that number (if any) shall be deleted from
the catalog. The application shall ensure that message identifiers are
in ascending order within a single set, but need not be contiguous. The
application shall ensure that the length of
is in the range [0,
- $quote n
This line specifies an optional quote character
which can be used to surround
so that trailing
characters or null (empty) messages are visible in a message source
line. By default, or if an empty
directive is supplied, no quoting of
shall be recognized.
Empty lines in a message text source file shall be ignored. The
effects of lines starting with any character other than those defined
above are implementation-defined.
Text strings can contain the special characters and escape sequences
defined in the following table:
|The escape sequence|
| || |
|specify the value of the desired character. If the character following a || || || |
|is not one of those specified, the|
|shall be ignored.|| |
|followed by a|
|is also used to continue a string on the following line. Thus, the|
|following two lines describe a single message string:|
|1 This line continues \|
|to the next line|
|which shall be equivalent to:|
|1 This line continues to the next line|
|The following exit values shall be returned:|
|An error occurred.|
|Message catalogs produced by|
|are binary encoded, meaning that their portability cannot be guaranteed|
|between different types of machine. Thus, just as C programs need to|
|be recompiled for each type of machine, so message catalogs must be|
|The Base Definitions volume of POSIX.1-2017,|
|Portions of this text are reprinted and reproduced in electronic form|
|from IEEE Std 1003.1-2017, Standard for Information Technology|
|-- Portable Operating System Interface (POSIX), The Open Group Base|
|Specifications Issue 7, 2018 Edition,|
|Copyright (C) 2018 by the Institute of|
|Electrical and Electronics Engineers, Inc and The Open Group.|
|In the event of any discrepancy between this version and the original IEEE and|
|The Open Group Standard, the original IEEE and The Open Group Standard|
|is the referee document. The original Standard can be obtained online at|
|Any typographical or formatting errors that appear|
|in this page are most likely|
|to have been introduced during the conversion of the source files to|
|man page format. To report such errors, see|