Indent reads a C program in, rearranges the layout, and outputs a
new C program that will compile to the same executable binary as
the original one. The difference between the input and output is
that the output is in a standard layout determined by a large
number of options. For most of the options there are two choic-
es, one that enables it and one that disables it. If indent is
called with no file files, it operates as a filter. If called
with one file name, that file is reformatted and the result re-
places the original file. A backup is created, however, with the
suffix .BAK. If it is called with two file names, the first one
is the input file and the second one is the output file. Only
one file can be reformatted at a time (e.g., one cannot call in-
dent with *.c as argument; this is an error and will not work.).
Many options are available. If you want to format a program to
the official MINIX format, use pretty, which calls indent with
the proper options and then postprocesses the output. The op-
tions listed below control the formatting style.
OPTION
: -bad, -nbad If -bad is specified, a blank line is forced
after every block of declarations. Default: -nbad.
OPTION
: -bap, -nbap If -bap is specified, a blank line is forced
after every procedure body. Default: -nbap.
OPTION
: -bbb, -nbbb If -bbb is specified, a blank line is forced
before every block comment. Default: -nbbb.
OPTION
: -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.
OPTION
: -bl, -br Specifying -bl lines up compound statements like
this:
if (...)
{
code
} Specifying -br (the default) makes them look like this:
if (...) {
code
}
OPTION
: -cn The column in which comments on code start. The de-
fault is 33.
OPTION
: -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.
OPTION
: -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.
OPTION
: -ce, -nce Enables (disables) forcing elses to cuddle up
to the immediately preceding }. The default is -ce.
OPTION
: -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 in-
dentation added to indicate the nesting, unless -lp is in effect.
-ci defaults to the same value as -i.
OPTION
: -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. The default is
-cli0. (This is the only option that takes a fractional argu-
ment.)
OPTION
: -dn 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.
OPTION
: -din Specifies the indentation, in character positions,
from a declaration keyword to the following identifier. The de-
fault is -di16.
OPTION
: -dj, -ndj -dj left justifies declarations. -ndj indents
declarations the same as code. The default is -ndj.
OPTION
: -ei, -nei Enables (disables) special else-if processing.
If enabled, ifs following elses will have the same indentation as
the preceding if statement. The default is -ei.
OPTION
: -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.
OPTION
: -in The number of spaces for one indentation level. The
default is 8.
OPTION
: -ip, -nip Enables (disables) the indentation of parameter
declarations from the left margin. The default is -ip.
OPTION
: -ln Maximum length of an output line. The default is 78.
OPTION
: -lp, -nlp Lines up code surrounded by parenthesis in con-
tinuation lines. 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.
OPTION
: -npro Causes the profile files, .indent.pro in both the
current directory and the user's home directory to be ignored.
OPTION
: -pcs, -npcs If true (-pcs) all procedure calls will have
a space inserted between the name and the (. The default is
-npcs.
OPTION
: -ps, -nps If true (-ps) the pointer following operator ->
will be surrounded by spaces on either side. The default is
-nps.
OPTION
: -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.
OPTION
: -sc, -nsc Enables (disables) the placement of asterisks
(*) at the left edge of all comments. The default is -sc.
OPTION
: -sob, -nsob If -sob is specified, indent will swallow op-
tional blank lines. You can use this to get rid of blank lines
after declarations. The default is -nsob.
OPTION
: -st Causes indent to take its input from stdin, and put
its output to stdout.
OPTION
: -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 #typedefs. 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 typedefs.
OPTION
: -troff Causes indent to format the program for processing
by troff. It will produce a fancy listing in much the same spir-
it as vgrind. If the output file is not specified, the default
is standard output, rather than formatting in place.
OPTION
: -v, -nv The -v flag 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 either your login directory and/or the cur-
rent directory and including whatever switches you like. Switch-
es in .indent.pro in the current directory override those in your
login directory (with the exception of -T type definitions, which
just accumulate). If indent is run and a profile file exists,
then it is read to set up the program's defaults. The switches
should be separated by spaces, tabs or newlines. Switches on the
command line, however, override profile switches. 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. All other comments
are treated as straight text. Indent fits as many words (sepa-
rated 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 indenta-
tion 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 fur-
ther to the right, and the right margin may be automatically ex-
tended 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 pe-
culiarities introduced. Indent understands a substantial amount
about the syntax of C, but it has a forgiving parser. It at-
tempts to cope with the usual sorts of incomplete and misformed
syntax. In particular, the use of macros like:
#define forever for(;;) is handled properly.