NAME

       cflow - generate a C-language flowgraph

SYNOPSIS

       cflow [-ADIPSTUabdfilmnopqrsvx] [-D NAME[=DEFN]] [-I DIR] [-P DIR] [-U NAME] [-d NUMBER] [-f NAME] [-i
       CLASSES] [-m NAME] [-o FILE] [-p NUMBER] [-s SYMBOL:[=]TYPE] [--all] [--[no-]ansi] [--[no-]brief]
       [--cpp=COMMAND] [--debug=[NUMBER]] [--define=NAME[=DEFN]] [--depth=NUMBER] [--[no-]emacs] [--format=NAME]
       [--include=CLASSES] [--include-dir=DIR] [--level-indent=ELEMENT] [--main=NAME] [--no-cpp] [--no-main]
       [--no-preprocess] [--[no-]number] [--[no-]omit-arguments] [--[no-]omit-symbol-names] [--output=FILE]
       [--prepend-path=DIR] [--preprocess=[COMMAND]] [--[no-]print-level] [--profile=FILE] [--pushdown=NUMBER]
       [--[no-]reverse] [--start=NAME] [--symbol=SYMBOL:[=]TYPE] [--target=NAME] [--[no-]tree] [--undefine=NAME]
       [--[no-]use-indentation] [--[no-]verbose] [--xref] [FILE]...

       cflow [-?V] [--help] [--usage] [--version]

NOTE

       This  manpage is a short description of GNU cflow.  For a detailed discussion, including examples and us‐
       age recommendations, refer to the GNU Cflow Manual available in texinfo format.  If the info  reader  and
       the cflow documentation are properly installed on your system, the command

           info cflow

       should give you access to the complete manual.

       You can also view the manual using the info mode in emacs(1), or find it in various formats online at

           http://www.gnu.org/software/cflow/manual

       If  any  discrepancies occur between this manpage and the GNU Cflow Manual, the later shall be considered
       the authoritative source.

DESCRIPTION

       Cflow analyzes a collection of input files written in C programming language and writes to standard  out‐
       put a graph charting dependencies between various functions.

OPTIONS

   General-purpose options
       -d, --depth=NUMBER
              Set the depth at which the flowgraph is cut off.  By default the depth is not limited.

       --debug[=NUMBER]
              Set debugging level.

       -f, --format=NAME
              Use given output format NAME. Valid names are dot (DOT language), gnu (the default) and posix.

       -i, --include=CLASSES
              Include specified classes of symbols.  The ^or- symbol excludes the classes that follow it.  Valid
              classes are:

              _ (underscore)
                     Symbols whose names begin with an underscore.

              s      Static symbols

              t      Typedefs (for cross-references only).

              x      All data symbols, both external and static

       -o, --output=FILE
              Set output file name (default is -, meaning stdout).

       -r, --[no-]reverse
              Print (don't print) reverse call tree.

       -x, --xref
              Produce cross-reference listing only.

       -v, --verbose
              Enable verbose error diagnostics.

       --no-verbose
              Cancel effect of any prior --verbose options.

   Program initialization
       These  options manipulate cflow profiles.  A profile is a set of cflow options intended to be applied to‐
       gether.  Profiles are used, among others, to provide settings for specific versions of the C language.

       Each profile is given a unique name and stored in a file named NAME.cfo located in profile  search  path.
       The  default  search  path is determined at compile time, and normally consists of the following directo‐
       ries:

       ~/.cflow.d
              (~/ stands for the user home directory)

       /usr/share/cflow/site-init

       /usr/share/cflow/VERSION
              (VERSION is the version of cflow)

       Examine the output of the cflow --help command, to obtain the search path used by your version of cflow.

       -P, --prepend-path=DIR
              Add DIR at the beginning of the profile search path.

       --profile=NAME
              Read options from the named profile.  A profile is a text file containing a set of cflow  options.
              This  option causes lookup of the file NAME.cfo in profile search path.  The file is read, and all
              options from it processed as though they appeared in that point of the command line.

       -q     Don't load default profile.

              Default profile is stored in file default.cfo, located in the search path.  Unless the  -q  option
              is given, that file is processed at startup.

   Parser control
       -a, --ansi
              Accept only sources in ANSI C.

       --no-ansi
              Don't assume input files are written in ANSI C.

       -D, --define=NAME[=DEFN]
              Predefine NAME as a macro.

       -I, --include-dir=DIR
              Add the directory DIR to the list of directories to be searched for header files.

       -p, --pushdown=NUMBER
              Set initial token stack size to NUMBER.

       --preprocess[=COMMAND], --cpp[=COMMAND]
              Run the specified preprocessor command.

       --no-preprocess, --no-cpp
              Disable preprocessing.

       -s, --symbol=SYMBOL:[=]TYPE
              Register  SYMBOL with given TYPE, or define an alias (if := is used). Valid types are: keyword (or
              kw), modifier, qualifier, identifier, type, wrapper, and declaration.  Any  unambiguous  abbrevia‐
              tion of the above is also accepted.

       -S, --use-indentation
              Rely on indentation to solve suspicious constructs.

       --no-use-indentation
              Don't use indentation in parsing (default).

       --target=NAME
              Show only graphs leading from start symbols to this function; multiple options are allowed.

       -U, --undefine=NAME
              Cancel any previous definition of NAME.

   Output control
       -A, --all
              Produce  graphs for all global functions in the program.  Use this option if your program contains
              functions which are not directly reachable from main().

              Output consists of separate flow graphs for each top-level function defined in the program.  These
              graphs will be placed after the graph for main() (if it exists), and will be ordered lexicographi‐
              cally by the function name.

              If used twice, graphs for all global functions (whether top-level or not) will be displayed.

       -b, --brief
              Brief output.

       --no-brief
              Disable brief output.

       --emacs
              Format output for use with GNU Emacs.

       --no-emacs
              Disable the effect of the previous --emacs option.

       -l, --print-level
              Print nesting level along with the call tree.

       --no-print-level
              Don't print nesting level.

       --level-indent=ELEMENT
              Control graph appearance.

       -m, --main=NAME
              Assume main function is NAME.  This option can be given multiple times. A separate graph  will  be
              drawn for each function given as its argument.

       --no-main
              Assume  there's no main function in the program.  This option has the same effect as --all, except
              that, if the program do define the main function, it will be treated as any other functions,  i.e.
              it  will not be placed at the top of output, but in its place as per the lexicographic ordering of
              function names.  See also the description of --all.

       -n, --number
              Print line numbers.

       --no-number
              Don't print line numbers.

       --omit-arguments
              Do not print argument lists in function declarations.

       --no-omit-arguments
              Print argument lists in function declarations (the default).

       --omit-symbol-names
              Do not print symbol names in declaration strings.

       --no-omit-symbol-names
              Print symbol names in declaration strings (the default).

       -T, --tree
              Draw ASCII art tree.

       --no-tree
              Disable tree output.

   Informational options
       These options instruct the program to output the requested piece of information and exit.

       -?, --help
              Print a short help summary.

       --usage
              Print a summary of available options.

       -V, --version
              Print program version.

RETURN VALUE

       0      Successful completion.

       1      Fatal error occurred.

       2      Some input files cannot be read or parsed.

       3      Command line usage error.

SEE ALSO

       Online copies of GNU cflow documentation in various formats can be found at:

           http://www.gnu.org/software/cflow/manual

AUTHORS

       Sergey Poznyakoff <gray@gnu.org>.

BUG REPORTS

       Report bugs to <bug-cflow@gnu.org>.

COPYRIGHT

       Copyright © 2014-2025 Sergey Poznyakoff
       License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
       This is free software: you are free to change and redistribute it.  There is NO WARRANTY, to  the  extent
       permitted by law.

CFLOW                                             May 10, 2025                                          CFLOW(1)