CFLOW(1P) POSIX Programmer's Manual CFLOW(1P)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
cflow — generate a C-language flowgraph (DEVELOPMENT)
SYNOPSIS
cflow [−r] [−d num] [−D name[=def]]... [−i incl] [−I dir]...
[−U dir]... file...
DESCRIPTION
The cflow utility shall analyze a collection of object files or assem‐
bler, C-language, lex, or yacc source files, and attempt to build a
graph, written to standard output, charting the external references.
OPTIONS
The cflow utility shall conform to the Base Definitions volume of
POSIX.1‐2008, 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:
−d num 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.
−i incl 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 <under‐
score>. The default shall be to exclude these func‐
tions (and data if −i x 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.
OPERANDS
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 out‐
put 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.
STDIN
Not used.
INPUT FILES
The input files shall be object files or assembler, C-language, lex, or
yacc source files.
ENVIRONMENT VARIABLES
The following environment variables shall affect the execution of
cflow:
LANG Provide a default value for the internationalization vari‐
ables that are unset or null. (See the Base Definitions vol‐
ume of POSIX.1‐2008, Section 8.2, Internationalization Vari‐
ables 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.
ASYNCHRONOUS EVENTS
Default.
STDOUT
The flowgraph written to standard output shall be formatted as follows:
"%d %s:%s\n", <reference number>, <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 defini‐
tion. 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 defi‐
nition can be found. For undefined references, only "<>" shall be writ‐
ten.
STDERR
The standard error shall be used only for diagnostic messages.
OUTPUT FILES
None.
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
Files produced by lex and yacc cause the reordering of line number dec‐
larations, and this can confuse cflow. To obtain proper results, the
input of yacc or lex must be directed to cflow.
EXAMPLES
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: <>
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
c99, lex, yacc
The Base Definitions volume of POSIX.1‐2008, Chapter 8, Environment
Variables, Section 12.2, Utility Syntax Guidelines
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/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.ker‐
nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 CFLOW(1P)
