NAME
indent - indent and format a C program source file
SYNOPSIS
indent input-file [ output-file ] [ [ -bap | -nbap ]
[ -bacc | -nbacc ] [ -bad | -nbad ] [ -bbb | -nbbb ]
[ -bc | -nbc ] [ -bl ] [ -br ] [ -bs | -nbs ] [ -cn ]
[ -cdn ] [ -cdb | -ncdb ] [ -ce | -nce ] [ -cin ] [ -clin ]
[ -dn ] [ -din ] [ -dj | -ndj ] [ -eei | -neei ]
[ -ei | -nei ] [ -fc1 | -nfc1 ] [ -in ] [ -ip | -nip ]
[ -ln ] [ -lcn ] [ -lp | -nlp ] [ -pcs | -npcs ] [ -npro ]
[ -psl | -npsl ] [ -sc | -nsc ] [ -sob | -nsob ] [ -st ]
[ -T typename ] [ -troff ] [ -v | -nv ]
DESCRIPTION
indent is a C program formatter. It reformats the C program
in the input-file according to the switches. The switches
which can be specified are described below. They may appear
before or after the file names.
Note: if you only specify an input-file, the formatting is
done "in-place", that is, the formatted file is written back
into input-file and a backup copy of input-file is written
in the current directory. If input-file is named
/blah/blah/file, the backup file is named file.BAK.
If output-file is specified, indent checks to make sure it
is different from input-file.
OPTIONS
The options listed below control the formatting style
imposed by indent.
-bacc,-nbacc
If -bacc is specified, a blank line is forced
around every conditional compilation block. For
example, in front of every #ifdef and after every
#endif. Other blank lines surrounding these will
be swallowed. Default: -nbacc.
-bad,-nbad
If -bad is specified, a blank line is forced after
every block of declarations. Default: -nbad.
-bap,-nbap
If -bap is specified, a blank line is forced after
every procedure body. Default: -nbap.
-bbb,-nbbb
If -bbb is specified, a blank line is forced
before every block comment. Default: -nbbb.
-bc,-nbc If -bc is specified, then a NEWLINE is forced
after each comma in a declaration. -nbc turns off
this option. Default: -bc.
-br,-bl Specifying -bl lines up compound statements like
this:
if (...)
{
code
}
Specifying -br (the default) makes them look like
this:
if (...) {
code
}
-bs,-nbs
Enable (disable) the forcing of a blank after sizeof.
Some people believe that sizeof should appear as though
it were a procedure call (-nbs, the default) and some
people believe that since sizeof is an operator, it
should always be treated that way and should always
have a blank after it.
-cn The column in which comments on code start.
Default: -c33.
-cdn The column in which comments on declarations start. The
default is for these comments to start in the same
column as those on code.
-cdb,-ncdb
Enable (disable) the placement of comment delimiters on
blank lines. With this option enabled, comments look
like this:
/*
* this is a comment
*/
Rather than like this:
/* this is a comment */
This only affects block comments, not comments to the right
of code. Default: -cdb.
-ce,-nce
Enables (disables) forcing else's to cuddle up to the
immediately preceding `}'. Default: -ce.
-cin Sets the continuation indent to be the value of n.
Continuation lines will be indented the value of n from
the beginning of the first line of the statement.
Parenthesized expressions have extra indentation added
to indicate the nesting, unless -lp is in effect. -ci
defaults to the same value as -i.
-clin
Cause case labels to be indented n tab stops to the
right of the containing switch statement. -cli0.5
causes case labels to be indented half a tab stop.
Default: -cli0.
-dn Control the placement of comments which are not to the
right of code. Default: -d1 means that such comments
are placed one indentation level to the left of code.
Specifying -d0 lines up these comments with the code.
See the section on comment indentation below.
-din Specify the indentation, in character positions, from a
declaration keyword to the following identifier.
Default: -di16.
-dj,-ndj
-dj left justifies declarations. -ndj indents declara-
tions the same as code. Default: -ndj.
-ei,-nei
If -ei is enabled, ifs following elses will have the
same indentation as the preceding if statement. If it
is disabled, ifs following elses will be indented one
extra level. Default: -ei.
-eei,-neei
If -eei is specified, an extra expression indent is
applied on continuation lines of the expression part of
if() and while(). These continuation lines will be
indented one extra level - twice instead of just once.
This is to avoid the confusion between the continued
expression and the statement that follows the if() or
while(). Default: -neei.
-fc1,-nfc1
Enables (disables) the formatting of comments that
start in column 1. Often, comments whose leading `/'
is in column 1 have been carefully hand formatted by
the programmer. In such cases, -nfc1 should be used.
Default: -fc1.
-in The number of spaces for one indentation level. The
default is one tab stop, -i8.
-ip,-nip
Enables (disables) the indentation of parameter
declarations from the left margin. Default: -ip .
-ln Maximum length of an output line with a trailing com-
ment. Default: -l78.
-lcn Sets the line length for block comments to n. It
defaults to being the same as the usual line length as
specified with -l.
-lp,-nlp
Lines up code surrounded by parenthesis in continuation
lines. If a line has a left parenthesis which is not
closed on that line, then continuation lines will be
lined up to start at the character position just after
the left parenthesis. For example, here is how a piece
of continued code looks with -nlp in effect:
p1 = first_procedure(second_procedure(p2, p3),
third_procedure(p4, p5));
With -lp in effect (the default) the code looks some-
what clearer:
p1 = first_procedure(second_procedure(p2, p3),
third_procedure(p4, p5));
Inserting a couple more NEWLINE characters we get:
p1 = first_procedure(second_procedure(p2,
p3),
third_procedure(p4,
p5));
This example was generated with -lp.
-npro
Ignore the profile files, ./.indent.pro and
~/.indent.pro.
-pcs , -npcs
If true (-pcs) all procedure calls and declarations in
the source code will have a space inserted between the
name and the '('. Default: -npcs
-psl , -npsl
If true (-psl) the names of procedures being defined
are placed in column 1 - their types, if any, will be
left on the previous lines. Default: -psl.
-sc,-nsc
Enables (disables) the placement of asterisks (`*'s) at
the left edge of all comments. Default: -sc.
-sob,-nsob
If -sob is specified, indent will swallow optional
blank lines. You can use this to get rid of blank
lines after declarations. Default: -nsob.
-st indent takes its input from the standard input, and put
its output to the standard output.
-T typename
Add typename to the list of type keywords. Names accu-
mulate: -T can be specified more than once. You need
to specify all the typenames that appear in your pro-
gram that are defined by typedefs - nothing will be
harmed if you miss a few, but the program won't be for-
matted as nicely as it should. This sounds like a
painful thing to have to do, but it is really a symptom
of a problem in C: typedef causes a syntactic change
in the language and indent cannot find all typedefs.
-troff
Causes indent to format the program for processing by
troff. It will produce a fancy listing in much the
same spirit as vgrind. If the output file is not
specified, the default is standard output, rather than
formatting in place. The usual way to get a troffed
listing is with the command
indent -troff program.c | troff -mindent
-v,-nv
-v turns on "verbose" mode, -nv turns it off. When in
verbose mode, indent reports when it splits one line of
input into two or more lines of output, and gives some
size statistics at completion. Default: -nv.
USAGE
You may set up your own "profile" of defaults to indent by
creating a file called .indent.pro in either your login
directory or the current directory and including whatever
switches you like. An .indent.pro in the current directory
takes precedence over the one in your login directory. If
indent is run and a profile file exists, then it is read to
set up the program's defaults. Switches on the command
line, though, always override profile switches. The
switches should be separated by SPACE, TAB, or NEWLINE char-
acters.
Comments
Boxed indent assumes that any comment with a dash
or star immediately after the start of com-
ment (that is, `/*-'or`/**') is a comment
surrounded by a box of stars. Each line of
such a comment is left unchanged, except that
its indentation may be adjusted to account
for the change in indentation of the first
line of the comment.
Straight text All other comments are treated as straight
text. indent fits as many words (separated
by SPACE, TAB, or NEWLINE characters) on a
line as possible. Blank lines break para-
graphs.
Comment indentation
If a comment is on a line with code it is started in the
comment column, which is set by the -cn command line parame-
ter. Otherwise, the comment is started at n indentation
levels less than where code is currently being placed, where
n is specified by the -dn command line parameter. If the
code on a line extends past the comment column, the comment
starts further to the right, and the right margin may be
automatically extended in extreme cases.
Preprocessor lines
In general, indent leaves preprocessor lines alone. The
only reformatting that it will do is to straighten up trail-
ing comments. It leaves imbedded comments alone. Condi-
tional compilation (#ifdef...#endif) is recognized and
indent attempts to correctly compensate for the syntactic
peculiarities introduced.
C syntax
indent understands a substantial amount about the syntax of
C, but it has a "forgiving" parser. It attempts to cope
with the usual sorts of incomplete and misformed syntax. In
particular, the use of macros like:
#define forever for(;;)
is handled properly.
/*INDENT OFF*/ /*INDENT ON*/
All text between these two comments gets left alone. There-
fore, when you put source code between these comments, it
will not be affected by the reformatting.
FILES
./.indent.pro profile file
~/.indent.pro profile file
SEE ALSO
troff(1)
BUGS
A common mistake that often causes grief is typing:
indent *.c
to the shell in an attempt to indent all the C programs in a
directory.