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INDENT(1) General Commands Manual INDENT(1)
NAME
indent - indent and format C program source
SYNOPSIS
indent [input-file [output-file]] [-bacc | -nbacc] [-bad | -nbad]
[-badp | -nbadp] [-bap | -nbap] [-bbb | -nbbb] [-bc | -nbc]
[-bl | -br] [-bs | -nbs] [-cn] [-cdn] [-cdb | -ncdb] [-ce | -nce]
[-cin] [-clin] [-cs | -ncs] [-dn] [-din] [-dj | -ndj]
[-eei | -neei] [-ei | -nei] [-fbs | -nfbs] [-fc1 | -nfc1]
[-fcb | -nfcb] [-in] [-ip | -nip] [-ln] [-lcn] [-ldin] [-lp |
-nlp] [-lpl | -nlpl] [-npro] [-Pfile] [-pcs | -npcs] [-psl |
-npsl] [-sc | -nsc] [-sob | -nsob] [-st] [-ta] [-Ttypename] [-tsn]
[-Ufile] [-ut | -nut] [-v | -nv] [--version]
DESCRIPTION
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 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 such blocks will be swallowed.
Default: -nbacc.
-bad, -nbad If -bad is specified, a blank line is forced after every
block of declarations. Default: -nbad.
-badp, -nbadp This is vaguely similar to -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 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: -nbc.
-bl, -br Specifying -bl lines up compound statements like this:
if (...)
{
code
}
Specifying -br (the default) makes them look like this:
if (...) {
code
}
-bs, -nbs Whether a blank should always be inserted after sizeof.
The default is -nbs.
-cn The column in which comments on code start. The default
is 33.
-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 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 of `else's to cuddle up to the
immediately preceding `}'. The default is -ce.
-cin 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.
-clin Causes case labels to be indented n indentation levels to
the right of the containing switch statement. -cli0.5
causes case labels to be indented half an indentation
level. The default is -cli0.
-cs, -ncs Control whether parenthesized type names in casts are
followed by a space or not. The default is -ncs.
-dn Controls the placement of comments which are not to the
right of code. For example, -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.
-din Specifies the indentation, in character positions, of
global variable names and all struct/union member names
relative to the beginning of their type declaration. The
default is -di16.
-dj, -ndj -dj left justifies declarations. -ndj indents
declarations the same as code. The default is -ndj.
-eei, -neei Enables (disables) extra indentation on continuation
lines of the expression part of if and while statements.
These continuation lines will be indented one extra
level. The default is -neei.
-ei, -nei Enables (disables) special 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.
-fbs, -nfbs Enables (disables) splitting the function declaration and
opening brace across two lines. The default is -fbs.
-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. The
default is -fc1.
-fcb, -nfcb Enables (disables) the formatting of block comments (ones
that begin with `/*\n'). Often, block comments have been
not so carefully hand formatted by the programmer, but
reformatting that would just change the line breaks is
not wanted. In such cases, -nfcb should be used. Block
comments are then handled like box comments. The default
is -fcb.
-in The number of columns 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.
-ln Maximum length of an output line. The default is 78.
-lcn Maximum length of an output line in a block comment. The
default is 0, which means to limit block comment lines in
accordance with -l.
-ldin Specifies the indentation, in character positions, of
local variable names relative to the beginning of their
type declaration. The default is for local variable
names to be indented by the same amount as global ones.
-lp, -nlp Lines up code surrounded by parentheses in continuation
lines. With -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 With -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 Causes the profile files, `./.indent.pro' and
`~/.indent.pro', to be ignored.
-Pfile Read profile from file.
-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 (`*'s) 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.
-st Causes indent to take its input from stdin and put its
output to stdout.
-ta Automatically add all identifiers ending in "_t" to the
list of type keywords.
-Ttypename 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 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.
-tsn Assumed distance between tab stops. The default is 8.
-Ufile Adds type names from file to the list of type keywords.
-ut, -nut Enables (disables) the use of tab characters in the
output. The default is -ut.
-v, -nv -v turns on `verbose' mode; -nv turns it off. When in
verbose mode, indent reports its configuration on the
standard error output. The default is -nv.
--version Causes 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.
Comments
`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.
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 parameter. 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. Conditional
compilation (#ifdef...#endif) is recognized and indent attempts to
correctly compensate for the syntactic peculiarities introduced.
C syntax
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.
ENVIRONMENT
The indent utility uses the HOME environment variable.
FILES
./.indent.pro profile file
~/.indent.pro profile file
HISTORY
The indent command appeared in 4.2BSD.
BUGS
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.
NetBSD 10.99 June 9, 2023 NetBSD 10.99