This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       Files  produced  by  lex  and yacc cause the reordering of line number declarations, and this can confuse
       cflow.  To obtain proper results, the input of yacc or lex must be directed to cflow.

       Default.

       Default.

       Thefollowingsectionsareinformative.

       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 http://www.opengroup.org/unix/online.html .

       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
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                                         CFLOW(1POSIX)

       The  cflow  utility  shall  analyze  a  collection of object files or assembler, C-language, lex, or yacc
       source files, and attempt to build a graph, written to standard output, charting the external references.

       The following environment variables shall affect the execution of cflow:

       LANG      Provide a default value for the internationalization variables that are unset or null. (See the
                 Base  Definitions  volume  of POSIX.1‐2017, Section8.2, InternationalizationVariables 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 when the -r option is used.

       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.

       Given the following in file.c:

           int i;
           int f();
           int g();
           int h();
           int
           main()
           {
               f();
               g();
               f();
           }
           int
           f()
           {
               i = h();
           }

       The command:

           cflow -i x file.c

       produces the output:

           1 main: int(), <file.c 6>
           2    f: int(), <file.c 13>
           3        h: <>
           4        i: int, <file.c 1>
           5    g: <>

       The following exit values shall be returned:

        0    Successful completion.

       >0    An error occurred.

       None.

       None.

       The input files shall be object files or assembler, C-language, lex, or yacc source files.

       cflow — generate a C-language flowgraph (DEVELOPMENT)

       The following operand is supported:

       file      The pathname of a file for which a graph is to be generated.  Filenames suffixed  by  .l  shall
                 shall  be taken to be lex input, .y as yacc input, .c as c99 input, and .i as the output of c99-E.  Such files shall be processed as appropriate, determined by their suffix.

                 Files suffixed by .s (conventionally  assembler  source)  may  have  more  limited  information
                 extracted from them.

       The cflow utility shall conform to the Base Definitions volume of  POSIX.1‐2017,  Section12.2,  UtilitySyntaxGuidelines,  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:

       -dnum    Indicate the depth at which the flowgraph is cut off. The application  shall  ensure  that  the
                 argument  num  is  a decimal integer. By default this is a very large number (typically greater
                 than 32000). Attempts to set the cut-off depth to a non-positive integer shall be ignored.

       -iincl   Increase the number of included symbols. The incl  option-argument  is  one  of  the  following
                 characters:

                 x     Include  external and static data symbols. The default shall be to include only functions
                       in the flowgraph.

                 _     (Underscore) Include names that begin with an <underscore>.   The  default  shall  be  to
                       exclude these functions (and data if -ix is used).

       -r        Reverse  the  caller:callee  relationship, producing an inverted listing showing the callers of
                 each function. The listing shall also be sorted in lexicographical order by callee.

       None.

       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.

       None.

c99, lex, yacc

       The Base Definitions volume of POSIX.1‐2017, Chapter8,  EnvironmentVariables,  Section12.2,  UtilitySyntaxGuidelines

       The standard error shall be used only for diagnostic messages.

       Not used.

       The flowgraph written to standard output shall be formatted as follows:

           "%d %s:%s\n", <referencenumber>, <global>, <definition>

       Each line of output begins with a reference (that is, line) number, followed by indentation of  at  least
       one  column  position  per  level.   This  is  followed  by  the  name  of the global, a <colon>, and its
       definition. Normally globals are only  functions  not  defined  as  an  external  or  beginning  with  an
       <underscore>;  see  the  OPTIONS  section  for the -i inclusion option. For information extracted from C-
       language source, the definition consists of an abstract type  declaration  (for  example,  char*)  and,
       delimited  by  angle  brackets,  the name of the source file and the line number where the definition was
       found. Definitions extracted from object files indicate the filename and location counter under which the
       symbol appeared (for example, text).

       Once a definition of a name has been written,  subsequent  references  to  that  name  contain  only  the
       reference number of the line where the definition can be found. For undefined references, only "<>" shall
       be written.

       cflow [-r][-d num][-D name[=def]]... [-i incl][-I dir]...
           [-U dir]... file...