cflow - Man Page

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 usage 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

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 output 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 together.  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 directories:

~/.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 abbreviation 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 lexicographically 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>.

Referenced By

htags(1).

May 10, 2025 CFLOW