NAME
indent —
indent and format C program
source
SYNOPSIS
indent |
[input-file
[output-file]]
[-bacc |
-nbacc] [-bad
| -nbad] [-bap
| -nbap] [-bbb
| -nbbb] [-bc
| -nbc]
[-bl]
[-br]
[-cn]
[-cdn]
[-cdb | -ncdb]
[-ce | -nce]
[-cin]
[-clin]
[-dn]
[-din]
[-ei | -nei]
[-eei | -neei]
[-fc1 | -nfc1]
[-in]
[-ip | -nip]
[-ln]
[-lcn]
[-lp | -nlp]
[-npro]
[-pcs | -npcs]
[-psl | -npsl]
[-sc | -nsc]
[-sob | -nsob]
[-st]
[-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
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.
-
-
- -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.
-
-
- -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:
Specifying -br (the default) makes them look like this:
-
-
- -bs,
-nbs
- If -bs is specified, a blank is forced
after sizeof. Default: -nbs.
-
-
- -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
- 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 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 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
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
- 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, from a
declaration keyword to the following identifier. Default:
-di16.
-
-
- -dj,
-ndj
- -dj left justifies declarations.
-ndj indents declarations the same as code. Default:
-ndj.
-
-
- -ei,
-nei
- Enables (disables) special else-if
processing. If it's enabled, an if following an
else will have the same indentation as the preceding
if statement. Default: -ei.
-
-
- -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.
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. Default:
-i8.
-
-
- -ip,
-nip
- Enables (disables) the indentation of parameter
declarations from the left margin. Default: -ip.
-
-
- -ln
- Maximum length of an output line. Default:
-l78.
-
-
- -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 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));
-
-
- -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 `('. 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
- Causes indent to take its input from
stdin, and put its output to stdout.
-
-
- -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 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 and indent can't find all
instances of typedef.
-
-
- -troff
- Causes indent to format the program for
processing by troff(1). It
will produce a fancy listing in much the same spirit as
vgrind(1). 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.
Default: -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. 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.
indent 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.
indent 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
-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. 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
indent uses the
HOME
environment
variable.
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 that often causes grief is typing:
indent *.c
to the shell in an attempt to indent all the C programs in a directory. This is
probably a bug, not a feature.