--- name: "perltidy" section: "1" platform: "linux" package: "perltidy" version: "20011020-1" release: "Debian 3.0 (Woody)" platforms: ["linux"] url: "https://new.carta.tech/perltidy" --- # perltidy(1) perltidy - a Perl script indenter and reformatter ``` perltidy [ options ] file1 file2 file3 ... (output goes to file1.tdy, file2.tdy, file3.tdy, ...) perltidy [ options ] file1 -o outfile perltidy [ options ] file1 -st >outfile perltidy [ options ] outfile ``` Perltidy reads a Perl script and writes an indented, reformatted script. The default formatting tries to follow the recommendations in [*perlstyle*(1)](/perlstyle/1.md). Many users will find enough information in the section on "EXAMPLES" to get started. New users may benefit from the short tutorial which comes with the distribution. The formatting can be controlled in detail with numerous input parameters, which are described in the section on "OPTIONS". ``` perltidy somefile.pl ``` This will produce a file *somefile.pl.tdy* containing the script reformatted using the default options, which approximate the style suggested in [*perlstyle*(1)](/perlstyle/1.md). Perltidy never changes the input file. ``` perltidy *.pl ``` Execute perltidy on all .pl files in the current directory with the default options. The output will be in files with an appended *.tdy* extension. For any file with an error, there will be a file with extension *.ERR*. ``` perltidy -gnu somefile.pl ``` Execute perltidy on file *somefile.pl* with a style which approximates the GNU Coding Standards for C programs. The output will be *somefile.pl.tdy*. ``` perltidy -i=3 somefile.pl ``` Execute perltidy on file *somefile.pl*, with 3 columns for each level of indentation (**-i=3**) instead of the default 4 columns. There will not be any tabs in the reformatted script, except for any which already exist in comments, pod documents, quotes, and here documents. Output will be *somefile.pl.tdy*. ``` perltidy -i=3 -t somefile.pl ``` Same as the previous example, except that each set of 3 columns of indentation (**-i=3**) will be represented by one leading tab character (**-t**). ``` perltidy -ce -l=72 somefile.pl ``` Execute perltidy on file *somefile.pl* with all defaults except use "cuddled elses" (**-ce**) and a maximum line length of 72 columns (**-l=72**) instead of the default 80 columns. ``` perltidy -g somefile.pl ``` Execute perltidy on file *somefile.pl* and save a log file *somefile.pl.LOG* which shows the nesting of braces, parentheses, and square brackets at the start of every line. The entire command line is scanned for options, and they are processed before any files are processed. As a result, it does not matter whether flags are before or after any filenames. However, the relative order of parameters is important, with later parameters overriding the values of earlier parameters. For each parameter, there is a long name and a short name. The short names are convenient for keyboard input, while the long names are self-documenting and therefore useful in scripts. It is customary to use two leading dashes for long names, but one may be used. Most parameters which serve as on/off flags can be negated with a leading "n" (for the short name) or a leading "no" (for the long name). For example, the flag to use tabs is **-t** or **--tabs**. The flag to use no tabs (the default) is **-nt** or **--notabs**. Options may not be bundled together. In other words, options **-q** and **-g** may NOT be entered as **-qg**. Option names may be terminated early as long as they are uniquely identified. For example, instead of **-dump-token-types**, it would be sufficient to enter **-dump-tok**, or even **-dump-t**, to uniquely identify this command.\ **I/O control**\ Show summary of usage and exit.\ Name of the output file (only if a single input file is being processed). If no output file is specified, and output is not redirected to the standard output, the output will go to *filename.tdy*.\ Perltidy must be able to operate on an arbitrarily large number of files in a single run, with each output being directed to a different output file. Obviously this would conflict with outputting to the single standard output device, so a special flag, **-st**, is required to request outputting to the standard output. For example, ``` perltidy somefile.pl -st >somefile.new.pl ``` This option may only be used if there is just a single input file. When this option is used, perltidy will have to create a temporary copy of the output file, perltidy.TMPO, to feed to perl for syntax checking, unless allow syntax checking is disabled. This file will be deleted when the job finishes. The default is **-nst** or **-nostandard-output**.\ If perltidy detects an error when processing file *somefile.pl*, its default behavior is to write error messages to file *somefile.pl.ERR*. Use **-se** to cause all error meassages to be sent to the standard error output stream instead. This directive may be negated with **-nse**. Thus, you may place **-se** in a *.perltidyrc* and override it when desired with **-nse** on the command line.\ Setting **-w** causes perltidy to include any non-critical warning messages be reported as errors. These include messages about possible pod problems, possibly bad starting indentation level, and cautions about indirect object usage. The default, **-nw** or **--nowarning-output**, is not to include these warnings.\ Deactivate error messages and syntax checking (for running under an editor). For example, if you use a vi-style editor, such as vim, you may execute perltidy as a filter from within the editor using something like ``` :n1,n2!perltidy -q ``` where `"n1,n2"` represents the selected text. Without the **-q** flag, any error messages will mess up your screen. Besides, it is common to run perltidy on incomplete blocks from an editor, and you don't want to see any complaints about that. (Or maybe you do; in that case, be prepared to use your "undo" key).\ This causes perltidy to run `"perl -T -c"` to check syntax of input and output. The results are written to the *.LOG* file, which will be saved if an error is detected in the output script. The output script is not checked if the input script has a syntax error. To skip syntax checking, use **-nsyn** or **--nocheck-syntax**. Syntax checking is also deactivated by the **--quiet** flag, discussed above. The default is to do a syntax check.\ Save the *.LOG* file, which has many useful diagnostics. Perltidy always creates a *.LOG* file, but by default it is deleted unless a program bug is suspected. Setting the **-log** flag forces the log file to be saved.\ Set maximum interval between input code lines in the logfile. This purpose of this flag is to assist in debugging nesting errors. The value of `"n"` is optional. If you set the flag **-g** without the value of `"n"`, it will be taken to be 1, meaning that every line will be written to the log file. This can be helpful if you are looking for a brace, paren, or bracket nesting error. Setting **-g** also causes the logfile to be saved, so it is not necessary to also include **-log**. If no **-g** flag is given, a value of 50 will be used, meaning that at least every 50th line will be recorded in the logfile. This helps prevent excessively long log files. Setting a negative value of `"n"` is the same as not setting **-g** at all.\ Ignore any *.perltidyrc* command file. Normally, perltidy looks first in your current directory for a *.perltidyrc* file of parameters. (The format is described below). If it finds one, it applies those options to the initial default values, and then it applies any that have been defined on the command line. If no *.perltidyrc* file is found, it looks for one in your home directory. If you set the **-npro** flag, perltidy will not look for this file.\ Write a list of all options used to the *.LOG* file. This is useful for debugging command files. In the list, the status of on/off switches is indicated by a 0 for off and a 1 for on. Please see **--dump-options** for a simpler way to do this.\ Force perltidy to process binary files. Normally, perltidy skips files identified by the system as non-text. This flag causes all existing files to be processed.\ **Basic Options**\ Use n columns per indentation level (default n=4). See also **--tabs**.\ This flag defines the characters used to indicate the indentation level of each line of code to be tabs. Perltidy allows two possible ways to represent the indentation at the beginning of each line of code. You may either use one tab character per level of indentation (signified with the -t flag), or you may use n real space characters per level, (where n is defined by the -i flag). The choice depends upon which is most convenient for your editor or viewer. The default is to use ASCII space characters because they should be properly displayed on all editors or viewers, even though they are not always the most convenient for editing. Of course, you can always rerun perltidy to change the indentation characters. If you choose tabs, you will want to give the appropriate setting to your editor to display tabs as 4 blanks (or whatever value has been set with the **-i** command). Except for these possible tab indentation characters, Perltidy does not introduce any tab characters into your file, and it removes any tabs from the code (unless requested not to do so with **-fws**). If you have any tabs in your comments, quotes, or here-documents, they will remain.\ Use space (blank) characters instead of tabs for leading indentation. This is the default, following the recommendation in [*perlstyle*(1)](/perlstyle/1.md), although some programmers will prefer tabs.\ This flag is used to deactivate all formatting and line break changes. When it is in effect, the only change to the script will be indentation. And any flags controlling whitespace and newlines will be ignored. You might want to use this if you are perfectly happy with your whitespace and line breaks, and merely want perltidy to handle the indentation. (This also speeds up perltidy by about a factor of two, so it might be useful when perltidy is merely being used to help find a brace error in a large script). Setting this flag is equivalent to setting **--freeze-newlines** and **--freeze-whitespace**.\ **Whitespace Control**\ This flag causes your original whitespace to remain unchanged, and causes the rest of the whitespace commands in this section to be ignored.\ Here the term "tightness" will mean the closeness with which pairs of enclosing tokens, such as parentheses, contain the quantities within. A numerical value of 0, 1, or 2 defines the tightness, with 0 being least tight and 2 being most tight. The **-pt=n** or **--paren-tightness** parameter controls the space within parens. The example below shows the effect of the three possible values, 0, 1, and 2: ``` if ( ( my $len_tab = length( $tabstr ) ) > 0 ) { # -pt=0 if ( ( my $len_tab = length($tabstr) ) > 0 ) { # -pt=1 (default) if ((my $len_tab = length($tabstr)) > 0) { # -pt=2 ``` When n is 0, there is always a space to the right of a '(' and to the left of a ')'. For n=2 there is never a space. For n=1, the default, there is a space unless the quantity within the parens is a single token, such as an identifier or quoted string. Likewise, the parameter **-sbt=n** or **--square-bracket-tightness** controls the space within square brackets, as illustrated below. ``` $width = $col[ $j + $k ] - $col[ $j ]; # -sbt=0 $width = $col[ $j + $k ] - $col[$j]; # -sbt=1 (default) $width = $col[$j + $k] - $col[$j]; # -sbt=2 ``` Curly braces which do not contain code blocks are controlled by the parameter **-bt=n** or **--brace-tightness=n**. ``` $obj->{ $parsed_sql->{ 'table' }[0] }; # -bt=0 $obj->{ $parsed_sql->{'table'}[0] }; # -bt=1 (default) $obj->{$parsed_sql->{'table'}[0]}; # -bt=2 ``` And finally, curly braces which contain blocks of code are controlled by the parameter **-bbt=n** or **--block-brace-tightness=n** as illustrated in the example below. ``` %bf = map { $_ => -M $_ } grep { /\.deb$/ } dirents '.'; # -bbt=0 (default) %bf = map { $_ => -M $_ } grep {/\.deb$/} dirents '.'; # -bbt=1 %bf = map {$_ => -M $_} grep {/\.deb$/} dirents '.'; # -bbt=2 ``` Continuation indentation is extra indentation spaces applied when a long line is broken. The default is n=2, illustrated here: ``` my $level = # -ci=2 ( $max_index_to_go >= 0 ) ? $levels_to_go[0] : $last_output_level; ``` The same example, with n=0, is a little harder to read: ``` my $level = # -ci=0 ( $max_index_to_go >= 0 ) ? $levels_to_go[0] : $last_output_level; ``` By default, perltidy indents lists with 4 spaces, or whatever value is specified with **-i=n**. Here is a small list formatted in this way: ``` @month_of_year = ( 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec' ); ``` Use the **-lp** flag to add extra indentation to cause the data to begin past the opening parentheses of a sub call or list, or opening square bracket of an anonymous array, or opening curly brace of an anonymous hash. With this option set, the above list would become: ``` @month_of_year = ( 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec' ); ``` If the available line length (see **-l=n** ) does not permit this much space, perltidy will use less. This option has no effect on code BLOCKS, such as if/then/else blocks, which always use whatever is specified with **-i=n**. Also, the existance of line breaks and/or block comments between the opening and closing parens may cause perltidy to temporarily revert to its default method. Note: The **-lp** option may not be used together with the **-t** tabs option. If **-t** is specified, it will be ignored. In addition, any parameter which restricts the ability of perltidy to choose newlines will all conflict with **-lp** and will cause **-lp** to be deactivated. These include **-io**, **-fnl**, **-nanl**, and **-ndnl**.\ The **-icp** option leaves a list-termination line of the form `");"`, `"};"`, or `"];"` indented with the same indentation as the previous line. The previous example with **-icp** would give, ``` @month_of_year = ( # -icp 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec' ); ``` The **-icb** option leaves a brace which terminates a code block indented with the same indentation as the previous line. For example, ``` if ($task) { yyy(); } # -icb else { zzz(); } ``` The default is not to do this, indicated by **-nicb**.\ Block comments, meaning full-line comments, normally look best when they are indented to the same level as the code which follows them. This is the default behavior, but you may use **-nibc** to keep block comments left-justified. Here is an example: ``` # this comment is indented (-ibc, default) if ($task) { yyy(); } ``` Do not indent block comments. Here is an example: ``` # this comment is not indented (-nibc) if ($task) { yyy(); } ``` By default, perltidy tries to identify and align "hanging side comments", which are something like this: ``` my $IGNORE = 0; # This is a side comment # This is a hanging side comment # And so is this ``` A comment is considered to be a hanging side comment if it immediately follows a line with a side comment, or another hanging side comment. To deactivate this feature, use **-nhsc** or **--nohanging-side-comments**. If block comments are preceded by a blank line, they will not be mistaken as hanging side comments.\ When **-oll** is set, lines which cannot be broken into pieces less than the **maximum-line-length** will have their indentation removed to make them more readable. This is the default. This can mainly occur for long quoted strings and long comments. To prevent such out-denting, use **-noll** or **--nooutdent-long-lines**.\ Side comments look best when lined up several spaces to the right of code. Perltidy will try to keep comments at least n spaces to the right. The default is n=4 spaces.\ Some programmers prefer a space before all terminal semicolons. The default is for no such space, and is indicated with **-nsts** or **--nospace-terminal-semicolon**. ``` $i = 1 ; # -sts $i = 1; # -nsts (default) ``` Semicolons within **for** loops may sometimes be hard to see, particularly when commas are also present. This option places spaces on both sides of these special semicolons, and is the default. Use **-nsfs** or **--nospace-for-semicolon** to deactivate it. ``` for ( @a = @$ap, $u = shift @a ; @a ; $u = $v ) { # -sfs (default) for ( @a = @$ap, $u = shift @a; @a; $u = $v ) { # -nsfs ``` Setting **-asc** allows perltidy to add any missing optional semicolon at the end of a line which is followed by a closing curly brace on the next line. This is the default, and may be deactivated with **-nasc** or **--noadd-semicolons**.\ Setting **-dsm** allows perltidy to delete extra semicolons which are simply empty statements. This is the default, and may be deactivated with **-ndsm** or **--nodelete-semicolons**. (Such semicolons are not deleted, however, if they would promote a side comment to a block comment).\ Setting this option allows perltidy to add certain whitespace improve code readability. This is the default. If you do not want any whitespace added, but are willing to have some whitespace deleted, use **-naws**. (Use **-fws** to leave whitespace completely unchanged).\ Setting this option allows perltidy to remove some old whitespace between characters, if necessary. This is the default. If you do not want any old whitespace removed, use **-ndws** or **--nodelete-old-whitespace**.\ For those who want more detailed control over the whitespace around tokens, there are four parameters which can directly modify the default whitespace rules built into perltidy for any token. They are: **-wls=s** or **--want-left-space=s**, **-nwls=s** or **--nowant-left-space=s**, **-wrs=s** or **--want-right-space=s**, **-nwrs=s** or **--nowant-right-space=s**. These parameters are each followed by a quoted string, **s**, containing a list of token types. No more than one of each of these parameters should be specified, because repeating a command-line parameter always overwrites the previous one before perltidy ever sees it. To illustrate how these are used, suppose it is desired that there be no space on either side of the token types **= + - / \***. The following two parameters would specify this desire: ``` -nwls="= + - / *" -nwrs="= + - / *" ``` (Note that the token types are in quotes, and that they are separated by spaces). With these modified whitespace rules, the following line of math: ``` $root = -$b + sqrt( $b * $b - 4. * $a * $c ) / ( 2. * $a ); ``` becomes this: ``` $root=-$b+sqrt( $b*$b-4.*$a*$c )/( 2.*$a ); ``` These parameters should be considered to be hints to perltidy rather than fixed rules, because perltidy must try to resolve conflicts that arise between them and all of the other rules that it uses. One conflict that can arise is if, between two tokens, the left token wants a space and the right one doesn't. In this case, the token not wanting a space takes priority. It is necessary to have a list of all token types in order to create this type of input. Such a list can be obtained by the command **-dump-token-types**.\ **-tqw** or **--trim-qw** provide the default behavior of trimming spaces around multiline `"qw"` quotes and indenting them appropriately. **-ntqw** or **--notrim-qw** cause leading and trailing whitespace around multi-line `"qw"` quotes to be left unchanged. This option will not normally be necessary, but was added for testing purposes, because in some versions of perl, trimming `"qw"` quotes changes the syntax tree.\ **Line Break Control**\ If you do not want any changes to the line breaks in your script, set **-fnl**, and they will remain fixed, and the rest of the commands in this section will be ignored. You may want to use **-noll** with this.\ The default maximum line length is n=80 characters. Perltidy will try to find line break points to keep lines below this length. However, long quotes and side comments may cause lines to exceed this length. Setting **-l=0** is equivalent to setting **-l=(a large number)**. \ A blank line will be introduced before a full-line comment. This is the default. Use **-nbbc** or **--noblanks-before-comments** to prevent such blank lines from being introduced.\ A blank line will be introduced before a **sub** definition, unless it is a one-liner or preceded by a comment. A blank line will also be introduced before a **package** statement and a **BEGIN** and **END** block. This is the default. The intention is to help display the structure of a program by setting off certain key sections of code. This is negated with **-nbbs** or **--noblanks-before-subs**. \ A blank line will be introduced before blocks of coding delimited by **for**, **foreach**, **while**, **until**, and **if**, **unless**, in the following circumstances:\ The block is not preceded by a comment.\ The block is not a one-line block.\ The number of consecutive non-blank lines at the current indentation depth is at least **-lbl** (see next section). This is the default. The intention of this option is to introduce some space within dense coding. This is negated with **-nbbb** or **--noblanks-before-blocks**.\ This controls how often perltidy is allowed to add blank lines before certain block types (see previous section). The default is 8. Entering a value of **0** is equivalent to entering a very large number.\ This parameter specifies the maximum number of consecutive blank lines in the output script. The default is n=1. If the input file has more than n consecutive blank lines, the number will be reduced to n.\ Blank lines governed by the above flags, **-bbb**, **-bbs**, and **-bbc**, will be deleted. (But essential blank lines above pod documents will be retained). This is NOT the default.\ Retain blank lines, including those which do not corresponding to flags **-bbb**, **-bbs**, and **-bbc**. This is the default. The number of blanks retained is subject to the limit imposed by **--maximum-consecutive-blank-lines**, however.\ Enable the "cuddled else" style, in which `"else"` and `"elsif"` are follow immediately after the curly brace closing the previous block. The default is not to use cuddled elses, and is indicated with the flag **-nce** or **--nocuddled-else**. Here is a comparison of the alternatives: ``` if ($task) { yyy(); } else { # -ce zzz(); } ``` ``` if ($task) { yyy(); } else { # -nce (default) zzz(); } ``` Use the flag **-bl** to place the opening brace on a new line: ``` if ( $input_file eq '-' ) # -bl { important_function(); } ``` This flag applies to all structural blocks, including sub's (unless the **-sbl** flag is set -- see next item). The default style, **-nbl**, places an opening brace on the same line as the keyword introducing it. For example, ``` if ( $input_file eq '-' ) { # -nbl (default) ``` The flag **-sbl** can be used to override the value of **-bl** for opening sub braces. For example, ``` perltidy -sbl ``` produces this result: ``` sub foo { if (!defined($_[0])) { print("Hello, World\n"); } else { print($_[0], "\n"); } } ``` This flag is negated with **-nsbl**. If **-sbl** is not specified, the value of **-bl** is used.\ The flag **-bli** is the same as **-bl** but in addition it causes one unit of continuation indentation ( see **-ci** ) to be placed before an opening and closing brace associated with the keywords **if**, **elsif**, **else**, **unless**, **for**, **foreach**, **sub**, **while**, **until**, and also with a preceding label. For example, ``` if ( $input_file eq '-' ) # -bli { important_function(); } ``` The default style, **-nbl** places the opening brace on a new line if it does not fit on the same line as the opening keyword, like this: ``` if ( $bigwasteofspace1 && $bigwasteofspace2 ⎪⎪ $bigwasteofspace3 && $bigwasteofspace4 ) { big_waste_of_time(); } ``` To force the opening brace to always be on the right, use the **-bar** flag. In this case, the above example becomes ``` if ( $bigwasteofspace1 && $bigwasteofspace2 ⎪⎪ $bigwasteofspace3 && $bigwasteofspace4 ) { big_waste_of_time(); } ``` A conflict occurs if both **-bl** and **-bar** are specified.\ By default, perltidy first deletes all old line break locations, and then it looks for optimal break points to match the desired line length. Use **-ndnl** or **--nodelete-old-newlines** to force perltidy to retain all old line break points. \ By default, perltidy will add line breaks when necessary to create continuations of long lines and to improve the script appearance. Use **-nanl** or **-noadd-newlines** to prevent any new line breaks. This flag does not prevent perltidy from eliminating existing line breaks; see **-freeze-newlines** to completely prevent changes to line break points.\ Two command line parameters provide some control over whether a line break should be before or after specific token types. **-wba=s** or **--want-break-after=s**, and **-wbb=s** or **--want-break-before=s**. These parameters are each followed by a quoted string, **s**, containing a list of token types (separated only by spaces). No more than one of each of these parameters should be specified, because repeating a command-line parameter always overwrites the previous one before perltidy ever sees it. By default, perltidy breaks **after** these token types:\ % + - \* / x != == \>= \<= =~ !~ \< \> ⎪ & \>= \<\ \= \*\*= += \*= &= \<\<= &&= -= /= ⎪= \>\>= ⎪⎪= .= %= ^= x= And perltidy breaks **before** these token types by default:\ . \<\< \>\> -\> && ⎪⎪ To illustrate, to cause a break after a concatenation operator, `"'.'"`, rather than before it, the command line would be ``` -wba="." ``` As another example, the following command would cause a break before math operators `"'+'"`, `"'-'"`, `"'/'"`, and `"'*'"`: ``` -wbb="+ - / *" ``` These commands should work well for most of the token types that perltidy uses (use **--dump-token-types** for a list). However, for a few token types there may be conflicts with hardwired logic which cause unexpected results. An example is the comma, which is hardwired to go at the end of lines in certain cases. Hopefully, this restriction will be removed in the future. Another example is curly braces, which should be controlled with the parameter **bl** provided for that purpose.\ **Styles**\ **-gnu** gives an approximation to the GNU Coding Standards (which do not apply to perl) as they are sometimes implemented. At present, this style overrides the default style with the following parameters: ``` -lp -bl -noll -pt=2 -bt=2 -sbt=2 -icp ``` **Other Controls**\ When perltidy writes a formatted text file, it has the ability to also send selected text to a file with a *.TEE* extension. This text can include comments and pod documentation. The relevant commands are: **-tac** or **--tee-all-comments**, **-tbc** or **--tee-block-comments**, **-tsc** or **--tee-side-comments**, and **-tp** or **--tee-pod**. The negatives of these commands also work, and are the defaults.\ Perltidy can selectively delete comments and pod documentation. The commands to do this are: **-dac** or **--delete-all-comments**, **-dbc** or **--delete-block-comments**, **-dsc** or **--delete-side-comments**, and **-dp** or **--delete-pod**. The negatives of these commands also work, and are the defaults. When block comments are deleted, any leading 'hash-bang' will be retained. Also, if the **-x** flag is used, any system commands before a leading hash-bang will be retained (even if they are in the form of comments).\ If you use perltidy frequently, you probably won't be happy until you create a *.perltidyrc* file to avoid typing commonly-used parameters. Perltidy will first look in your current directory for a command file named *.perltidyrc*, and if it does not find one, it will look in your home directory. If it does not find one there, it will look for a system-wide file */usr/local/etc/perltidyrc*, and failing to find one there it will look for */etc/perltidyrc*. Note that the system-wide files do not have a leading dot. This file is free format, and simply a list of parameters, just as they would be entered on a command line. Any number of lines may be used, with any number of parameters per line, although it may be easiest to read with one parameter per line. Blank lines are ignored, and text after a '#' is ignored to the end of a line. Here is an example of a *.perltidyrc* file: ``` # This is a simple of a .perltidyrc configuration file # This implements a highly spaced style -se # errors to standard error output -w # show all warnings -bl # braces on new lines -pt=0 # parens not tight at all -bt=0 # braces not tight -sbt=0 # square brackets not tight ``` The parameters in the *.perltidyrc* file are installed first, so any parameters given on the command line will have priority over them. To avoid confusion, perltidy ignores any command in the .perltidyrc file which would cause some kind of dump and an exit. These are: ``` -h -v -ddf -dln -dop -dsn -dtt -dwls -dwrs -ss ``` There are several options may be helpful in debugging a *.perltidyrc* file. First, **-log** will force a *.LOG* file to be written, which contains the path to the *.perltidyrc* file, if any, and a listing of its parameter settings. Second, **-opt** will force a *.LOG* file to be written with a complete listing of all option flags in use for a run, taking into account the default settings, the *.perltidyrc* file, plus any command line options. Third, the parameters in the *.perltidyrc* file can be ignored with the **-npro** option. Finally, the commands **-dump-options**, **-dump-defaults**, **-dump-long-names**, and **-dump-short-names**, all described below, may all be helpful.\ A special notation is available for use in a *.perltidyrc* file for creating an abbreviation for a group of options. This can be used to create a shorthand for one or more styles which are frequently, but not always, used. The notation is to group the options within curly braces which are preceded by the name of the alias (without leading dashes), like this: ``` newword { -opt1 -opt2 } ``` where **newword** is the abbreviation, and **opt1**, etc, are existing parameters *or other abbreviations*. The main syntax requirement is that the new abbreviation must begin on a new line. Space before and after the curly braces is optional. For a specific example, the following line ``` airy {-bl -pt=0 -bt=0 -sbt=0} ``` could be placed in a *.perltidyrc* file, and then invoked at will with ``` perltidy -airy somefile.pl ``` (Either `"-airy"` or `"--airy"` may be used).\ By default, perltidy examines the input file and tries to determine the starting indentation level. While it is often zero, it may not be zero for a code snippet being sent from an editing session. If the default method does not work correctly, or you want to change the starting level, use **-sil=n**, to force the starting level to be n.\ If your script has leading lines of system commands or other text which are not valid perl code, and which are separated from the start of the perl code by a "hash-bang" line, ( a line of the form `"#!...perl"` ), you must use the **-x** flag to tell perltidy not to parse and format any lines before the "hash-bang" line. This option also invokes perl with a -x flag when checking the syntax. This option was originally added to allow perltidy to parse interactive VMS scripts, but it should be used for any script which is normally invoked with `"perl -x"`.\ Perltidy attempts to place comma-separated arrays of values in tables which can be vertically aligned. The number of fields is, by default, chosen to be the largest even number which fits in the current page width (defined by **-l=n**). Usually this works well. There are two ways to control this formatting. The first is with the use of comments or empty lines. If there are any comments or blank lines between the opening and closing structural brace, parenthesis, or bracket containing the list, then the original line breaks will be used for the entire list instead. The second is with the parameter **--mft=n** or **--maximum-fields-per-table=n**. The default value for **n** is a large number, 40. If the computed number of fields for any table exceeds **n**, then it will be reduced to **n**. While this value should probably be left unchanged as a general rule, it might be used on a small section of code to force a list to have a particular number of fields per line, and then a single comment could be introduced somewhere to freeze the formatting in future applications of perltidy, like this: ``` @month_of_year = ( # -mft=2 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec' ); ``` Vertical alignment refers to lining up similar tokens vertically, like this: ``` my $lines = 0; # checksum: #lines my $bytes = 0; # checksum: #bytes my $sum = 0; # checksum: system V sum ``` Once the perltidy vertical aligner "locks on" to a pattern, such as defined by the "=" and "#" in the above example, it retains the pattern for as long as possible. However, a blank line or full-line comment will cause it to forget the pattern and start looking for another. Thus, a single blank line can be introduced to force the aligner to stop aligning when it is undesirable.\ The goal of perltidy is to improve the readability of files, but there are two commands which have the opposite effect, **--mangle** and **--extrude**. They are actually merely aliases for combinations of other parameters. Both of these strip all possible whitespace, but leave comments and pod documents, so that they are essentially reversible. The difference between these is that **--mangle** puts the fewest possible line breaks in a script while **--extrude** puts the maximum possible. Note that these options do not provided any meaningful obfuscation, because perltidy can be used to reformat the files. A useful application of **--mangle** is the following: ``` perltidy -mangle myfile.pl -st ⎪ perltidy -o myfile.pl.new ``` This will form the maximum possible number of one-line blocks (see next section), and can sometimes help clean up a badly formatted script.\ There are a few points to note regarding one-line blocks. A one-line block is something like this, ``` if ($x > 0) { $y = 1 / $x } ``` where the contents within the curly braces is short enough to fit on a single line. With few exceptions, Perltidy retains existing one-line blocks, if it is possible within the line-length constraint, but it does not attempt to form new ones. In other words, Perltidy will try to follow the one-line block style of the input file. If an existing one-line block is longer than the maximum line length, however, it will be broken into multiple lines. When this happens, perltidy checks for and adds any optional terminating semicolon (unless the **-nasc** option is used) if the block is a code block. The main exception is that Perltidy will attempt to form new one-line blocks following the keywords `"map"`, `"eval"`, and `"sort"`, because these code blocks are often small and most clearly displayed in a single line. Occasionally it is helpful to introduce line breaks in lists containing a '=\>' symbol, which is sometimes called a "comma-arrow". To force perltidy to introduce breaks in a one-line block containing comma arrows, use the **--break-after-comma-arrows**, or **-baa**, flag. For example, given the following single line, Perltidy will not add any line breaks: ``` bless { B => $B, Root => $Root } => $package; -nbaa (default) ``` To introduce breaks to show the structure, use **-baa**: ``` bless { -baa B => $B, Root => $Root } => $package; ``` One-line block rules can conflict with the cuddled-else option. When the cuddled-else option is used, perltidy retains existing one-line blocks, even if they do not obey cuddled-else formatting. Occasionally, when one-line blocks get broken because they exceed the available line length, the formatting will violate the requested brace style. If this happens, reformatting the script a second time should correct the problem.\ The following flags are available for debugging: **--dump-defaults** or **-ddf** will write the default option set to standard output and quit **--dump-options** or **-dop** will write current option set to standard output and quit. **--dump-long-names** or **-dln** will write all command line long names (passed to Get\_options) to standard output and quit. **--dump-short-names** or **-dsn** will write all command line short names to standard output and quit. **--dump-token-types** or **-dtt** will write a list of all token types to standard output and quit. **--dump-want-left-space** or **-dwls** will write the hash `%want_left_space` to standard output and quit. See the section on controlling whitespace around tokens. **--dump-want-right-space** or **-dwrs** will write the hash `%want_right_space` to standard output and quit. See the section on controlling whitespace around tokens. **-DEBUG** will write a file with extension *.DEBUG* for each input file showing the tokenization of all lines of code.\ The first `$VERSION` line of a file which might be eval'd by MakeMaker is passed through unchanged except for indentation. Use **--nopass-version-line**, or **-npvl**, to deactivate this feature. If the AutoLoader module is used, perltidy will continue formatting code after seeing an \_\_END\_\_ line. Use **--nolook-for-autoloader**, or **-nlal**, to deactivate this feature. Likewise, if the SelfLoader module is used, perltidy will continue formatting code after seeing a \_\_DATA\_\_ line. Use **--nolook-for-selfloader**, or **-nlsl**, to deactivate this feature.\ The flag **-html** causes perltidy to write an html file with extension *.html*. So, for example, the following command ``` perltidy -html somefile.pl ``` will produce a syntax-colored html file named *somefile.pl.html* which may be viewed with a browser. Documentation for this option has been moved to a separate man page, *perl2web*(1). The following list shows all short parameter names which allow a prefix 'n' to produce the negated form: ``` D anl asc aws bbb bbc bbs bli baa syn ce dac dbc dnl dws dp dsm dsc ddf dln dop dsn dtt dwls dwrs f fll hsc html ibc icb icp lp log lal x lsl bl sbl oll pvl q opt sfs sts se st sob t tac tbc tp tsc tqw w ``` Equivalently, the prefix 'no' on the corresponding long names may be used.\ Perltidy should work properly on most Perl scripts. It does a lot of self-checking, but still, it is possible that an error could be introduced and go undetected. Therefore, it is essential to make careful backups and to test reformatted scripts. The main current limitation is that perltidy does not scan modules included with 'use' statements. This makes it necessary to guess the context of any bare words introduced by such modules. Perltidy has good guessing algorithms, but they are not infallible. When it must guess, it leaves a message in the log file. If you encounter a bug, please report it.\ Perltidy indents but does not reformat comments and `"qw"` quotes. Perltidy does not in any way modify the contents of here documents or quoted text, even if they contain source code. (You could, however, reformat them separately). Perltidy does not format 'format' sections in any way. And, of course, it does not modify pod documents.\ When standard input is used, the log file, if saved, is *perltidy.LOG*, and any errors are written to *perltidy.ERR* unless the **-se** flag is set. These are saved in the current working directory. If syntax checking is used, a temporary copy of the input file will be created in the current working directory called *perltidy.TMPI*, but it will be removed when perltidy finishes. When standard output and syntax checking are used, a temporary copy of the output file will be created in the current working directory called *perltidy.TMPO*. It will be removed when perltidy finishes.\ The following file extensions are used by perltidy, and files with these extensions may be overwritten or deleted: *.tdy*, *.ERR*, *.LOG*, *.TEE*, *.TMPI*, *.TMPO*.\ Perltidy does not operate on files for which the run could produce a file with a duplicated file extension. These extensions are *.tdy*, *.LOG*, *.ERR*, *.TEE*, *.TMPI*, *.TMPO*. The purpose of this rule is to prevent generating confusing filenames such as *somefile.tdy.tdy.tdy*. *perl2web*(1), [*perlstyle*(1)](/perlstyle/1.md) This man page documents perltidy version 20011020. ``` Steven L. Hancock email: perltidy at users.sourceforge.net http://perltidy.sourceforge.net ``` Copyright (c) 2000, 2001 by Steven L. Hancock This package is free software; you can redistribute it and/or modify it under the terms of the "GNU General Public License". Please refer to the file "COPYING" for details. This package is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the "GNU General Public License" for more details.