# gencat

## PROLOG



           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.
    


## 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 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.)
    
           _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.
    
           _The following sections are informative._
    


## 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.
    


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