NAME
indent
—
indent and format C program
source
SYNOPSIS
indent |
[input-file [output-file]]
[-bad | -nbad ]
[-bap | -nbap ]
[-bbb | -nbbb ]
[-bc | -nbc ]
[-bl | -br ]
[-c n]
[-cd n]
[-cdb | -ncdb ]
[-ce | -nce ]
[-ci n]
[-cli n]
[-d n]
[-di n]
[-dj | -ndj ]
[-ei | -nei ]
[-fc1 | -nfc1 ]
[-i n]
[-ip | -nip ]
[-l n]
[-lc n]
[-lp | -nlp ]
[-npro ]
[-pcs | -npcs ]
[-psl | -npsl ]
[-sc | -nsc ]
[-sob | -nsob ]
[-st ]
[-T typename]
[-troff ]
[-ut | -nut ]
[-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 file.BAK exists, it is overwritten.
If output-file is specified,
indent
checks to make sure it is different from
input-file.
If no input-file is specified input is read from stdin and the formatted file is written to stdout.
The options listed below control the formatting style imposed by
indent
.
-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
. Note: This option currently has no effect. -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. The default is-nbc
. -bl
,-br
- Specifying
-bl
lines up compound statements like this:if (...) { code }
Specifying
-br
(the default) makes them look like this:if (...) { code }
-c
n- The column in which comments on code start. The default is 33.
-cd
n- 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
- Enables (disables) 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. The default is
-cdb
. -ce
,-nce
- Enables (disables) forcing “
else
”s to cuddle up to the immediately preceding ‘}
’. The default is-ce
. -ci
n- Sets the continuation indent to be n. Continuation
lines will be indented that far 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
. -cli
n- Causes 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. The default is-cli0
. -d
n- Controls the placement of comments which are not to the right of code.
Specifying
-d1
means that such comments are placed one indentation level to the left of code. The default,-d0
, lines up these comments with the code. See the section on comment indentation below. -di
n- Specifies the indentation, in character positions, from a declaration
keyword to the following identifier. The default is
-di16
. -dj
,-ndj
-dj
left justifies declarations.-ndj
indents declarations the same as code. The default is-ndj
.-ei
,-nei
- Enables (disables) special
else-if
processing. If it's enabled, anif
following anelse
will have the same indentation as the precedingif
statement. The default is-ei
. -fc1
,-nfc1
- Enables (disables) the formatting of comments that start in column 1.
Often, comments whose leading ‘
/
’ is in column 1 have been carefully formatted by the programmer. In such cases,-nfc1
should be used. The default is-fc1
. -i
n- The number of spaces for one indentation level. The default is 8.
-ip
,-nip
- Enables (disables) the indentation of parameter declarations from the left
margin. The default is
-ip
. Note: This option currently has no effect. -l
n- Maximum length of an output line. The default is 75. Note: This option currently has no effect.
-lc
n- Specify a column width for comments.
-lp
,-nlp
- Lines up code surrounded by parentheses 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 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));
The default is
-lp
. -npro
- Causes the profile files, ./.indent.pro and ~/.indent.pro, to be ignored.
-pcs
,-npcs
- If true (
-pcs
) all procedure calls will have a space inserted between the name and the ‘(
’. The default is-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. The default is-psl
. -sc
,-nsc
- Enables (disables) the placement of asterisks
(‘
*
’) at the left edge of all comments. The default is-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
. Note: This option currently has no effect. -st
- Causes
indent
to take its input from stdin, and put its output to stdout. -T
typename- Adds typename to the list of type keywords. Names
accumulate:
-T
can be specified more than once. You need to specify all the typenames that appear in your program that are defined bytypedef
- nothing will be harmed if you miss a few, but the program won't be formatted as nicely as it should. This sounds like a painful thing to have to do, but it's really a symptom of a problem in C:typedef
causes a syntactic change in the language andindent
can't find all instances oftypedef
. -troff
- Causes
indent
to format the program for processing by troff, producing a fancy listing. If the output file is not specified, the default is standard output, rather than formatting in place. -ut
,-nut
- Enables (disables) the use of tab characters in the output. Tabs are
assumed to be aligned on columns divisible by 8. The default is
-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
.
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. An
.indent.pro file 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.
Comments
‘Box’
comments.
indent
assumes that any comment with a dash, star,
or newline immediately after the start of comment (that is,
‘/*-
’,
‘/**
’, or
‘/*
’ followed immediately by a newline
character) 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 blanks,
tabs, or newlines) on a line as possible. Blank lines break paragraphs.
Comment indentation
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.
Preprocessor lines
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.
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.
ENVIRONMENT
HOME
- Used to locate the full path to ~/.indent.pro.
FILES
- ./.indent.pro
- profile file
- ~/.indent.pro
- profile file
HISTORY
The indent
command appeared in
4.2BSD.
BUGS
indent
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.