NAME

gencat - generate a formatted message catalog

SYNOPSIS

gencat catfile msgfile...

DESCRIPTION

The gencat utility shall merge the message text source file msgfile into a formatted message catalog catfile. The file catfile shall be created if it does not already exist. If catfile does exist, its messages shall be included in the new catfile. If set and message numbers collide, the new message text defined in msgfile shall replace the old message text currently contained in catfile.

OPTIONS

None.

OPERANDS

The following operands shall be supported:

catfile

A pathname of the formatted message catalog. If '-' is specified, standard output shall be used. The format of the message catalog produced is unspecified.

msgfile

A pathname of a message text source file. If '-' is specified for an instance of msgfile, standard input shall be used. The format of message text source files is defined in the EXTENDED DESCRIPTION section.

STDIN

The standard input shall not be used unless a msgfile operand is specified as '-'.

INPUT FILES

The input files shall be text files.

ENVIRONMENT VARIABLES

The following environment variables shall affect the execution of gencat:

LANG

Provide a default value for the internationalization variables that are unset or null. (See XBD Internationalization Variables for the precedence of internationalization variables used to determine the values of locale categories.)

LC_ALL

If set to a non-empty string value, override the values of all the other internationalization variables.

LC_CTYPE

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).

LC_MESSAGES

Determine the locale that should be used to affect the format and contents of diagnostic messages written to standard error.

NLSPATH

Determine the location of message catalogs for the processing of LC_MESSAGES.

ASYNCHRONOUS EVENTS

Default.

STDOUT

The standard output shall not be used unless the catfile operand is specified as '-'.

STDERR

The standard error shall be used only for diagnostic messages.

OUTPUT FILES

None.

EXTENDED DESCRIPTION

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 <blank> character. Any other <blank> characters are considered to be part of the subsequent field.

$set  n comment

This line specifies the set identifier of the following messages until the next $set or end-of-file appears. The n denotes the set identifier, which is defined as a number in the range [1, {NL_SETMAX}] (see the <limits.h> 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 $set 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 <nl_types.h> header defined in the Base Definitions volume of POSIX.1-2017).

$delset  n comment

This line deletes message set n from an existing message catalog. The n denotes the set number [1, {NL_SETMAX}]. Any string following the set number shall be treated as a comment.

$  comment

A line beginning with '$' followed by a <blank> shall be treated as a comment.

m message-text

The m denotes the message identifier, which is defined as a number in the range [1, {NL_MSGMAX}] (see the <limits.h> header). The message-text shall be stored in the message catalog with the set identifier specified by the last $set directive, and with message identifier m. If the message-text is empty, and a <blank> 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 message-text, 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 message-text is in the range [0, {NL_TEXTMAX}] (see the <limits.h> header).

$quote  n

This line specifies an optional quote character c, which can be used to surround message-text so that trailing <space> characters or null (empty) messages are visible in a message source line. By default, or if an empty $quote directive is supplied, no quoting of message-text 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:

Description	Symbol	Sequence
<newline>	NL(LF)	\n
Horizontal-tab	HT	\t
<vertical-tab>	VT	\v
<backspace>	BS	\b
<carriage-return>	CR	\r
<form-feed>	FF	\f
Backslash	\	\\
Bit pattern	ddd	\ddd

The escape sequence "\ddd" consists of <backslash> followed by one, two, or three octal digits, which shall be taken to specify the value of the desired character. If the character following a <backslash> is not one of those specified, the <backslash> shall be ignored.

A <backslash> followed by a <newline> 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

EXIT STATUS

The following exit values shall be returned:

 0

Successful completion.

>0

An error occurred.

CONSEQUENCES OF ERRORS

Default.

APPLICATION USAGE

Message catalogs produced by gencat 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 recreated via gencat.

EXAMPLES

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

iconv

XBD Environment Variables, <limits.h>, <nl_types.h>

CHANGE HISTORY

First released in Issue 3.

Issue 6

The normative text is reworded to avoid use of the term "must" for application requirements.

Issue 7

The gencat utility is moved from the XSI option to the Base.