indent.texinfo

indent为linux下代码自动格式化工具

@kindex -bbb
@kindex --blank-lines-before-block-comments
@kindex -nbbb
@kindex --no-blank-lines-before-block-comments
The @option{-bbb} option forces a blank line before every boxed comment
(@xref{Comments}.)
The @option{-nbbb} option does not force such blank lines.

@kindex -sob
@kindex --swallow-optional-blank-lines
@kindex -nsob
@kindex --leave-optional-blank-lines
The @option{-sob} option causes @command{indent} to swallow optional blank
lines (that is, any optional blank lines present in the input will be
removed from the output).  If the @option{-nsob} is specified, any blank
lines present in the input file will be copied to the output file.

@ifinfo
@menu
* -bad::                        More on the @option{-bad} option.
* -bap::                        More on the @option{-bap} option.
@end menu
@end ifinfo

@node -bad, -bap,  , Blank lines
@comment  node-name,  next,  previous,  up
@subsection --blank-lines-after-declarations

The @option{-bad} option forces a blank line after every block of
declarations.  The @option{-nbad} option does not add any such blank
lines.

For example, given the input
@example
@group
char *foo;
char *bar;
/* This separates blocks of declarations.  */
int baz;
@end group
@end example

@kindex -bad
@kindex --blank-lines-after-declarations
@kindex -nbad
@kindex --no-blank-lines-after-declarations
@noindent
@code{indent -bad} produces

@example
@group
char *foo;
char *bar;

/* This separates blocks of declarations.  */
int baz;
@end group
@end example

@noindent
and @code{indent -nbad} produces

@example
@group
char *foo;
char *bar;
/* This separates blocks of declarations.  */
int baz;
@end group
@end example

@node -bap,  , -bad, Blank lines
@comment  node-name,  next,  previous,  up
@subsection --blank-lines-after-procedures

@kindex -bap
@kindex --blank-lines-after-procedures
@kindex -nbap
@kindex --no-blank-lines-after-procedures
The @option{-bap} option forces a blank line after every procedure body.

For example, given the input

@example
@group
int
foo ()
@{
  puts("Hi");
@}
/* The procedure bar is even less interesting.  */
char *
bar ()
@{
  puts("Hello");
@}
@end group
@end example

@noindent
@code{indent -bap} produces

@example
@group
int
foo ()
@{
  puts ("Hi");
@}

/* The procedure bar is even less interesting.  */
char *
bar ()
@{
  puts ("Hello");
@}
@end group
@end example

@noindent
@c A better `group' would be better than `need'.
@need 1250
and @code{indent -nbap} produces

@example
@group
int
foo ()
@{
  puts ("Hi");
@}
/* The procedure bar is even less interesting.  */
char *
bar ()
@{
  puts ("Hello");
@}
@end group
@end example

@noindent
No blank line will be added after the procedure @code{foo}.

@node Comments, Statements, Blank lines, Indent Program
@comment  node-name,  next,  previous,  up
@section Comments
@cindex Comments

@command{indent} formats both C and C++ comments. C comments are begun with
@samp{/*}, terminated with @samp{*/} and may contain newline characters.
C++ comments begin with the delimiter @samp{//} and end at the newline.

@command{indent} handles comments differently depending upon their context.
@command{indent} attempts to distinguish between comments which follow
statements, comments which follow declarations, comments following
preprocessor directives, and comments which are not preceded by code of
any sort, i.e., they begin the text of the line (although not
neccessarily in column 1).

@command{indent} further distinguishes between comments found outside of
procedures and aggregates, and those found within them.  In particular,
comments beginning a line found within a procedure will be indented to
the column at which code is currently indented.  The exception to this a
comment beginning in the leftmost column;  such a comment is output
at that column.

@command{indent} attempts to leave @dfn{boxed comments} unmodified.  The
general idea of such a comment is that it is enclosed in a rectangle or
``box'' of stars or dashes to visually set it apart.  More precisely,
boxed comments are defined as those in which the initial @samp{/*} is
followed immediately by the character @samp{*}, @samp{=}, @samp{_}, or
@samp{-}, or those in which the beginning comment delimiter (@samp{/*})
is on a line by itself, and the following line begins with a @samp{*} in
the same column as the star of the opening delimiter.

Examples of boxed comments are:

@example
@group
/**********************
 * Comment in a box!! *
 **********************/

       /*
        * A different kind of scent,
        * for a different kind of comment.
        */
@end group
@end example

@command{indent} attempts to leave boxed comments exactly as they are found
in the source file.  Thus the indentation of the comment is unchanged,
and its length is not checked in any way.  The only alteration made is
that an embedded tab character may be converted into the appropriate
number of spaces.

If the @option{-bbb} option is specified, all such boxed comments will be
preceded by a blank line, unless such a comment is preceded by code.

@kindex -fca
@kindex --format-all-comments
@kindex -nfca
@kindex --dont-format-comments
@kindex -fc1
@kindex --format-first-column-comments
@kindex -nfc1
@kindex --dont-format-first-column-comments
Comments which are not boxed comments may be formatted, which means that
the line is broken to fit within a right margin and left-filled with
whitespace.  Single newlines are equivalent to a space, but blank lines
(two or more newlines in a row) are taken to mean a paragraph break.
Formatting of comments which begin after the first column is enabled
with the @option{-fca} option.  To format those beginning in column one,
specify @option{-fc1}.  Such formatting is disabled by default.

The right margin for formatting defaults to 78, but may be changed with
the @option{-lc} option.  If the margin specified does not allow the
comment to be printed, the margin will be automatically extended for the
duration of that comment.  The margin is not respected if the comment is
not being formatted.

@kindex -d@var{n}
@kindex --line-comments-indentation@var{n}
If the comment begins a line (i.e., there is no program text to its
left), it will be indented to the column it was found in unless the
comment is within a block of code.  In that case, such a comment will be
aligned with the indented code of that block (unless the comment began
in the first column).  This alignment may be affected by the @option{-d}
option, which specifies an amount by which such comments are moved to
the @emph{left}, or unindented.  For example, @option{-d2} places comments
two spaces to the left of code.  By default, comments are aligned with
code, unless they begin in the first column, in which case they are left
there by default --- to get them aligned with the code, specify @option{-fc1}.

@kindex -c@var{n}
@kindex --comment-indentation@var{n}
@kindex -cd@var{n}
@kindex --declaration-comment-column@var{n}
@kindex -cp@var{n}
@kindex --else-endif-column@var{n}
Comments to the right of code will appear by default in column 33.
This may be changed with one of three options.  @option{-c} will specify
the column for comments following code, @option{-cd} specifies the
column for comments following declarations, and @option{-cp} specifies
the column for comments following preprocessor directives @code{#else}
and @code{#endif}.

If the code to the left of the comment exceeds the beginning column,
the comment column will be extended to the next tabstop column past
the end of the code, or in the case of preprocessor directives, to one
space past the end of the directive.  This extension lasts only for
the output of that particular comment.

@kindex -cdb
@kindex --comment-delimiters-on-blank-lines
@kindex -ncdb
@kindex --no-comment-delimiters-on-blank-lines
The @option{-cdb} option places the comment delimiters on blank lines.
Thus, a single line comment like @code{/* Loving hug */} can be
transformed into:

@example
@group
/*
   Loving hug
 */
@end group
@end example

@kindex -sc
@kindex --star-left-side-of-comments
@kindex -nsc
@kindex --dont-star-comments
Stars can be placed at the beginning of multi-line comments with the
@option{-sc} option.  Thus, the single-line comment above can be
transformed (with @option{-cdb -sc}) into:

@example
@group
/*
 * Loving hug
 */
@end group
@end example

@node Statements, Declarations, Comments, Indent Program
@comment  node-name,  next,  previous,  up
@section Statements

@kindex -br
@kindex --braces-on-if-line
@kindex -bl
@kindex --braces-after-if-line
The @option{-br} or @option{-bl} option specifies how to format braces.

@c another paragraph that needs to be attached to its example.
@need 650
The @option{-br} option formats statement braces like this:

@example
@group
if (x > 0) @{
  x--;
@}
@end group
@end example

@noindent
The @option{-bl} option formats them like this:

@example
@group
if (x > 0)
  @{
    x--;
  @}
@end group
@end example

@kindex -bli@var{n}
@kindex --brace-indent@var{n}
If you use the @option{-bl} option, you may also want to specify the
@option{-bli} option.  This option specifies the number of spaces by
which braces are indented.  @option{-bli2}, the default, gives the
result shown above.  @option{-bli0} results in the following:

@example
@group
if (x > 0)
@{
  x--;
@}
@end group
@end example

@kindex -ce
@kindex --cuddle-else
@kindex -dce
@kindex --dont-cuddle-else
If you are using the @option{-br} option, you probably want to also use
the @option{-ce} option.  This causes the @code{else} in an if-then-else
construct to cuddle up to the immediately preceding @samp{@}}.  For
example, with @option{-br -ce} you get the following:

@example
@group
if (x > 0) @{
  x--;
@} else @{
  fprintf (stderr, "...something wrong?\n");
@}
@end group
@end example

@noindent
With @option{-br -nce} that code would appear as

@example
@group
if (x > 0) @{
  x--;
@}
else @{
  fprintf (stderr, "...something wrong?\n");
@}
@end group
@end example

@kindex -cdw
@kindex --cuddle-do-while
@kindex -ncdw
@kindex --dont-cuddle-do-while
This causes the @code{while} in a do-while
loop to cuddle up to the immediately preceding @samp{@}}.  For
example, with @option{-cdw} you get the following:

@example
@group
do @{
  x--;
@} while (x);
@end group
@end example

@noindent
With @option{-ncdw} that code would appear as

@example
@group
do @{
  x--;
@}
while (x);
@end group
@end example

@kindex -cli@var{n}
@kindex --case-indentation@var{n}
The @option{-cli} option specifies the number of spaces that case labels
should be indented to the right of the containing @code{switch}
statement.

@noindent
The default gives code like:

@example
@group
switch (i)
  @{
  case 0:
    break;
  case 1:
    @{
      ++i;
    @}
  default:
    break;
  @}
@end group