Difference between revisions of "PTop"

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Revision as of 18:05, 10 January 2007

PTOP - Free Pascal source formatter

ptop(1) ptop source beautifier ptop(1)


ptop - The FPC Pascal configurable source beautifier. Origin probably Pascal-TO-Pascal.


ptop [-v] [-i indent] [-b bufsize ] [-c optsfile] infile outfile


ptop is a more or less configurable source beautifier for pascal sources and specially the ones supported by FPC (which are more or less Turbo Pascal or Delphi 2.0 compatible). ptop belongs to the FPC utils package, which currently also contains ppdep, h2pas, ppudump and ppumove


ptop basically reformats "infile" and outputs the result to "outfile". It uses a configuration file explained further below, and can generate a default configuration file for you to edit. (not needed if you use the defaults)

Writes a short description of these switches.
-c configfile 
Read options from configuration file. A configuration file is not needed, ptop will revert to internal defaults then. See also -g
-i ident  
Sets the number of indent spaces used for BEGIN END; and other blocks.
-b bufsize 
Sets the buffer size to bufsize. Default 255, 0 is considered non-valid and ignored.
be verbose. Currently only outputs the number of lines read/written and some error messages.
-g configfile 
Writes a default configuration file to be edited to the file configfile

Try to play with ptop and its configfile until you find the effect you desire. The configurability and possibilities of ptop are quite large compared to shareware source beautifier found on e.g. SIMTEL.

ptop.cfg(5) ptop source beautifier config file ptop.cfg(5)


This is the main configuration file of the ptop FPC source beautifier

The configuration file for ptop(1) isn't necessarily called ptop.cfg, and is also not auto-loaded, so the name doesn't matter much. This man-page describes the structure of such a configuration file for ptop(1)


The structure of a ptop configuration file is a simple buildingblock repeated several (20-30) times, for each pascal keyword known to the ptop program. (see the default configuration file or ptopu.pp source to find out which keywords are known)

The basic building block of the configuration file consists out of one or two lines, describing how ptop should react on a certain keyword. First a line without square brackets with the following format:


If one of the options is "dindonkey" (see further below), a second line (with square brackets) is needed like this:


As you can see the block contains two types of identifiers , keywords(keyword and otherkeyword1..3 in above example) and options, (option1..3 above).

Keywords are the built-in valid Pascal structure-identifiers like BEGIN, END, CASE, IF, THEN, ELSE, IMPLEMENTATION. The default configuration file lists most of these. Besides the real Pascal keywords, some other codewords are used for operators and comment expressions. These are listed in the following table:

Name of codeword operator
casevar : in a case label (<>'colon')
becomes :=
delphicomment //
dopencomment (*
dclosecomment *)
opencomment {
closecomment }
semicolon ;
colon :
equals =
openparen [
closeparen ]
period .

The Options codewords define actions to be taken when the keyword before the equal sign is found.

Option does what
crsupp suppress CR before the keyword.
crbefore force CR before keyword (doesn't go with crsupp :) )
blinbefore blank line before keyword.
dindonkey de-indent on assiociated keywords (see below)
dindent deindent (always)
spbef space before
spaft space after
gobsym Print symbols which follow a

keyword but which do not affect layout.
Prints until terminators occur.
(terminators are hard-coded in pptop, still needs changing)

inbytab indent by tab.
crafter force CR after keyword.
upper prints keyword all uppercase
lower prints keyword all lowercase
capital capitalizes keyword: 1st letter uppercase, rest lowercase.

The option "dindonkey" requires some extra parameters, which are set by a second line for that keyword (the one with the square brackets), which is therefore only needed if the options contain "dinkdonkey" (contraction of de-indent on assiociated keyword). "dinkdonkey" deindents if any of the keywords specified by the extra options of the square-bracket line is found.


The lines



The keyword this is about is else , it's on the LEFT side of both equal signs. When the ptop parser finds ELSE, the options tell it to do the following things:

  • (crbefore) Don't allow other code on the line before the keyword. (ELSE alone on a line)
  • (dindonkey) De-indent on the keywords in square brackets line (if,then,else)
  • (inbytab) indent by tab.
  • (upper) uppercase the keyword (ELSE)

Try to play with the configfile until you find the effect you desire. The configurability and possibilities of ptop are quite large compared to shareware source beautifier found on e.g. SIMTEL.


The writer of the program, Michael van Canneyt, who also helped out explaining the format of ptop.cfg. Questions/corrections can be mailed to (removed)

Also thanks to the rest of the FPC development team. The program is a modernized (OOP, Streams, Delphi extensions) version based on a program by Peter Grogono, who in turn based his program on a Pascal pretty-printer written by Ledgard, Hueras, and Singer. See SIGPLAN Notices, Vol. 12, No. 7, July 1977, pages 101-105, and PP.DOC/HLP. This version of PP developed under Pascal/Z V4.0 or later.

Very minor modifications for Turbo Pascal made by Willett Kempton March 1984 and Oct 84.

Runs under 8-bit Turbo or 16-bit Turbo.

Toad Hall tweak, rewrite for TP 5, 28 Nov 89


ptop binary ptop(1) Other FPC utils ppdep(1) ppudump(1) ppumove(1) H2Pas(1)

original page: http://www.us.freepascal.org/tools/ptop.html

source code: