Updated: 2022/Sep/29

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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