INDENT(1) | General Commands Manual | INDENT(1) |
indent
— indent
and format C program source
indent |
[input-file [output-file]]
[-bacc | -nbacc ]
[-bad | -nbad ]
[-badp | -nbadp ]
[-bap | -nbap ]
[-bbb | -nbbb ]
[-bc | -nbc ]
[-bl | -br ]
[-bs | -nbs ]
[-c n]
[-cd n]
[-cdb | -ncdb ]
[-ce | -nce ]
[-ci n]
[-cli n]
[-cs | -ncs ]
[-d n]
[-di n]
[-dj | -ndj ]
[-ei | -nei ]
[-eei | -neei ]
[-fbs | -nfbs ]
[-fc1 | -nfc1 ]
[-fcb | -nfcb ]
[-i n]
[-ip | -nip ]
[-l n]
[-lc n]
[-ldi n]
[-lp | -nlp ]
[-lpl | -nlpl ]
[-npro ]
[-P file]
[-pcs | -npcs ]
[-ps | -nps ]
[-psl | -npsl ]
[-sc | -nsc ]
[-sob | -nsob ]
[-st ] [-ta ]
[-T typename]
[-ts n]
[-U file]
[-ut | -nut ]
[-v | -nv ]
[--version ] |
The indent
utility 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’ by default. The
extension used for the backup file may be overridden using the
SIMPLE_BACKUP_SUFFIX
environment variable.
If output-file is specified,
indent
checks to make sure that it is different from
input-file.
The options listed below control the formatting style imposed by
indent
.
-bacc
,
-nbacc
-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 such blocks
will be swallowed. Default: -nbacc
.-bad
,
-nbad
-bad
is specified, a blank line is forced after
every block of declarations. Default: -nbad
.-badp
,
-nbadp
-bad
except that it
only applies to the first set of declarations in a procedure (just after
the first `{') and it causes a blank line to be generated even if there
are no declarations. The default is -nbadp
.-bap
,
-nbap
-bap
is specified, a blank line is forced after
every procedure body. Default: -nbap
.-bbb
,
-nbbb
-bbb
is specified, a blank line is forced
before every block comment. Default: -nbbb
.-bc
,
-nbc
-bc
is specified, then a newline is forced
after each comma in a declaration. -nbc
turns off
this option. Default: -nbc
.-bl
,
-br
-bl
lines up compound statements like
this:
if (...) { code }
Specifying -br
(the default) makes
them look like this:
if (...) { code }
-bs
,
-nbs
-nbs
.-c
n-cd
n-cdb
,
-ncdb
/* * this is a comment */
Rather than like this:
/* this is a comment */
This only affects block comments, not comments to the right of
code. The default is -cdb
.
-ce
,
-nce
-ce
.-ci
n-lp
is in effect or
the continuation indent is exactly half of the main indent.
-ci
defaults to the same value as
-i
.-cli
nswitch
statement.
-cli0.5
causes case labels to be indented half a
tab stop. The default is -cli0
.-cs
,
-ncs
-ncs
.-d
n-d1
means that such comments are placed
one indentation level to the left of code. Specifying the default
-d0
lines up these comments with the code. See the
section on comment indentation below.-di
n-di16
.-dj
,
-ndj
-dj
left justifies declarations. -ndj
indents
declarations the same as code. The default is
-ndj
.-ei
,
-nei
else-if
processing. If
it is enabled, an if
following an
else
will have the same indentation as the
preceding if
statement. The default is
-ei
.-eei
,
-neei
if
and
while
statements. These continuation lines will be
indented one extra level. The default is
-neei
.-fbs
,
-nfbs
-fbs
.-fc1
,
-nfc1
-nfc1
should be used. The default is -fc1
.-fcb
,
-nfcb
-nfcb
should be
used. Block comments are then handled like box comments. The default is
-fcb
.-i
n-ip
,
-nip
-ip
.-l
n-lc
n-l
.-ldi
n-lp
,
-nlp
-lp
, if a line has a left paren which is not
closed on that line, then continuation lines will be lined up to start at
the character position just after the left paren. 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 somewhat clearer:
p1 = first_procedure(second_procedure(p2, p3), third_procedure(p4, p5));
Inserting two more newlines we get:
p1 = first_procedure(second_procedure(p2, p3), third_procedure(p4, p5));
-lpl
,
-nlpl
-lpl
, code surrounded by parentheses in
continuation lines is lined up even if it would extend past the right
margin. With -nlpl
(the default), such a line that
would extend past the right margin is moved left to keep it within the
margin, if that does not require placing it to the left of the prevailing
indentation level. These switches have no effect if
-nlp
is selected.-npro
-P
file-pcs
,
-npcs
-pcs
) all procedure calls will have a
space inserted between the name and the `('. The default is
-npcs
.-ps
,
-nps
-ps
) the pointer dereference operator
(`->') is treated like any other binary operator. The default is
-nps
.-psl
,
-npsl
-psl
) the names of procedures being
defined are placed in column 1 - their types, if any, will be left on the
previous lines. The default is -psl
.-sc
,
-nsc
-sc
.-sob
,
-nsob
-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
to take its input from stdin and put
its output to stdout.-ta
-T
typename-T
can be specified more than once.
You need to specify all the typenames that appear in your program that are
defined by typedef
- nothing will be harmed if you
miss a few, but the program will not be formatted 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
instances of typedef
.-ts
n-U
file-ut
,
-nut
-ut
.-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. The default is -nv
.--version
indent
to print its version number and
exit.You may set up your own `profile' of defaults to
indent
by creating a file called
.indent.pro in your login directory and/or the
current directory and including whatever switches you like. A `.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 spaces, tabs or newlines.
‘Box’
comments.
The indent
utility assumes that any comment with a
dash or star immediately after the start of comment (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. The
indent
utility fits as many words (separated by
blanks, tabs, or newlines) on a line as possible. Blank lines break
paragraphs.
If a comment is on a line with code it is started in the `comment
column', which is set by the
-c
n command line parameter.
Otherwise, the comment is started at n indentation
levels less than where code is currently being placed, where
n is specified by the
-d
n 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.
In general, indent
leaves preprocessor
lines alone. The only reformatting that it will do is to straighten up
trailing comments. It leaves embedded comments alone. Conditional
compilation (#ifdef...#endif
) is recognized and
indent
attempts to correctly compensate for the
syntactic peculiarities introduced.
The indent
utility 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 malformed syntax.
In particular, the use of macros like:
#define forever for(;;)
is handled properly.
The indent
utility uses the
HOME
environment variable.
The indent
command appeared in
4.2BSD.
The indent
utility has even more switches
than ls(1).
A common mistake is to try to indent all the C programs in a directory by typing:
indent *.c
This is probably a bug, not a feature.
June 28, 2023 | macOS 14.6 |