# cxref

## 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



           cxref — generate a C-language program cross-reference table
           (**DEVELOPMENT**)
    


## SYNOPSIS



           cxref **[** -cs**] [** -o _file_**] [** -w _num_**] [** -D _name_**[** =_def_**]]**... **[** -I _dir_**]**...
               **[** -U _name_**]**... _file_...
    


## DESCRIPTION



           The _cxref_ utility shall analyze a collection of C-language _file_ s
           and attempt to build a cross-reference table. Information from
           **#define** lines shall be included in the symbol table. A sorted
           listing shall be written to standard output of all symbols (auto,
           static, and global) in each _file_ separately, or with the **-c**
           option, in combination. Each symbol shall contain an <asterisk>
           before the declaring reference.
    


## OPTIONS



           The _cxref_ utility shall conform to the Base Definitions volume of
           POSIX.1‐2017, _Section 12.2_ , _Utility Syntax Guidelines_ , except that
           the order of the **-D** , **-I** , and **-U** options (which are identical to
           their interpretation by _c99_) is significant. The following options
           shall be supported:
    
           **-c** Write a combined cross-reference of all input files.
    
           **-s** Operate silently; do not print input filenames.
    
           **-o** _file_   Direct output to named _file_.
    
           **-w** _num_    Format output no wider than _num_ (decimal) columns. This
                     option defaults to 80 if _num_ is not specified or is less
                     than 51.
    
           **-D** Equivalent to _c99_.
    
           **-I** Equivalent to _c99_.
    
           **-U** Equivalent to _c99_.
    


## OPERANDS



           The following operand shall be supported:
    
           _file_      A pathname of a C-language source file.
    


## STDIN



           Not used.
    


## INPUT FILES



           The input files are C-language source files.
    


## ENVIRONMENT VARIABLES



           The following environment variables shall affect the execution of
           _cxref_ :
    
           _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_COLLATE_
                     Determine the locale for the ordering of the output.
    
           _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 be used for the cross-reference listing,
           unless the **-o** option is used to select a different output file.
    
           The format of standard output is unspecified, except that the
           following information shall be included:
    
            *  If the **-c** option is not specified, each portion of the listing
               shall start with the name of the input file on a separate
               line.
    
            *  The name line shall be followed by a sorted list of symbols,
               each with its associated location pathname, the name of the
               function in which it appears (if it is not a function name
               itself), and line number references.
    
            *  Each line number may be preceded by an <asterisk> (**'*'**) flag,
               meaning that this is the declaring reference. Other single-
               character flags, with implementation-defined meanings, may be
               included.
    


## STDERR



           The standard error shall be used only for diagnostic messages.
    


## OUTPUT FILES



           The output file named by the **-o** option shall be used instead of
           standard output.
    


## EXTENDED DESCRIPTION



           None.
    


## 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



           None.
    


## EXAMPLES



           None.
    


## RATIONALE



           None.
    


## FUTURE DIRECTIONS



           None.
    


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