NAME

indent − indent and format C program source

SYNTAX

indent input [output] [flags]

DESCRIPTION

The indent command is intended primarily as a C program formatter. Specifically, indent will indent code lines, align comments, insert spaces around operators where necessary and break up declaration lists as in “int a,b,c;”.

The indent command will not break up long statements to make them fit within the maximum line length, but it will flag lines that are too long.  Lines will be broken so that each statement starts a new line, and braces will appear alone on a line. See the −br option to inhibit this.  Also, an attempt is made to line up identifiers in declarations. 

The flags which can be specified follow. They may appear before or after the file names.  If the output file is omitted, the formatted file will be written back into input and a “backup” copy of input will be written in the current directory.  If input is named “/blah/blah/file”, the backup file will be named “.Bfile”.  If output is specified, indent checks to make sure it is different from input.

OPTIONS

The following flags may be used to control the formatting style imposed by indent.

−lnnn
Determines maximum length of output line.  The default is 75.

−cnnn
Determines column in which comments will start.  The default is 33.

−cdnnn
Determines column in which comments on declarations will start.  The default is for these comments to start in the same column as other comments.

−innn
Determines number of spaces for one indentation level.  The default is 4.

−dj,−ndj
Causes declarations to be left justified. −ndj will cause them to be indented the same as code.  The default is −ndj. 

−v,−nv
−v turns on “verbose” mode, −nv turns it off.  When in verbose mode, indent will report when it splits one line of input into two or more lines of output, and it will give some size statistics at completion. The default is −nv. 

−bc,−nbc
Forces newline after each comma in a declaration. −nbc will turn off this option.  The default is −bc. 

−dnnn
Controls the placement of comments which are not to the right of code. Specifying −d2 means that such comments will be placed two indentation levels to the left of code.  The default −d0 lines up these comments with the code.  See the section on comment indentation below. 

−br,−bl
Specifying −bl will cause complex statements to be lined up in a space order.  For example,

   if (...)
   {
       code
   }

Specifying −br (the default) will make them look like this:

   if (...) {
       code
   }

You may set up your own “profile” of defaults to indent by creating the file “.indent.pro” in your login directory and including whatever switches you like. 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, will always override profile switches. The profile file must be a single line of not more than 127 characters. The switches should be separated on the line by spaces or tabs.

Multiline expressions

The indent command will not break up complicated expressions that extend over multiple lines, but it will usually correctly indent such expressions which have already been broken up. Such an expression might end up looking like this:

x =
        (
            (Arbitrary parenthesized expression)
            +
            (
                (Parenthesized expression)
                *
                (Parenthesized expression)
            )
        );
 

Comments

The indent command recognizes four kinds of comments. They are: straight text, “box” comments, UNIX-style comments, and comments that should be passed through unchanged. The action taken with these various types are as follows:

“Box” comments.   The indent command assumes that any comment with a dash immediately after the start of comment (i.e. “/*−”) is a comment surrounded by a box of stars.  Each line of such a comment will be left unchanged, except that the first non-blank character of each successive line will be lined up with the beginning slash of the first line.  Box comments will be indented (see below).

“Unix-style” comments.   This is the type of section header which is used extensively in the UNIX system source.  If the start of comment (“/*”) appears on a line by itself, indent assumes that it is a UNIX-style comment.  These will be treated similarly to box comments, except the first non-blank character on each line will be lined up with the ‘*’ of the “/*”.

Unchanged comments.   Any comment which starts in column 1 will be left completely unchanged.  This is intended primarily for documentation header pages.  The check for unchanged comments is made before the check for UNIX-style comments. 

Straight text.   All other comments are treated as straight text.  Indent will fit as many words (separated by blanks, tabs, or new lines) on a line as possible.  Straight text comments will be indented. 

Comment indentation

Box, UNIX-style, and straight text comments may be indented.  If a comment is on a line with code it will be started in the “comment column”, which is set by the −cnnn command line parameter.  Otherwise, the comment will be started at nnn indentation levels less than where code is currently being placed, where nnn is specified by the −dnnn command line parameter.  (Indented comments will never be placed in column 1.)  If the code on a line extends past the comment column, the comment will be moved to the next line. 

RESTRICTIONS

Does not know how to format “long” declarations. 

DIAGNOSTICS

Diagnostic error messages, mostly to tell that a text line has been broken or is too long for the output line. 

FILES

.indent.proprofile file