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-b file’--break-file=file’
This option provides an alternative (to -W) method of describing
which characters make up words. It introduces the name of a
file which contains a list of characters which cannot be part of
one word; this file is called the Break file. Any character which
is not part of the Break file is a word constituent. If both options
-b and -W are specified, then -W has precedence and
-b is ignored.
When GNU extensions are enabled, the only way to avoid newline as a break character is to write all the break characters in the file with no newline at all, not even at the end of the file. When GNU extensions are disabled, spaces, tabs and newlines are always considered as break characters even if not included in the Break file.
-i file’--ignore-file=file’
The file associated with this option contains a list of words which will
never be taken as keywords in concordance output. It is called the
Ignore file. The file contains exactly one word in each line; the
end of line separation of words is not subject to the value of the
-S option.
-o file’--only-file=file’
The file associated with this option contains a list of words which will
be retained in concordance output; any word not mentioned in this file
is ignored. The file is called the Only file. The file contains
exactly one word in each line; the end of line separation of words is
not subject to the value of the -S option.
There is no default for the Only file. When both an Only file and an Ignore file are specified, a word is considered a keyword only if it is listed in the Only file and not in the Ignore file.
-r’--references’
On each input line, the leading sequence of non-white space characters will be
taken to be a reference that has the purpose of identifying this input
line in the resulting permuted index.
See Output formatting in ptx,
for more information about reference production.
Using this option changes the default value for option -S.
Using this option, the program does not try very hard to remove
references from contexts in output, but it succeeds in doing so
when the context ends exactly at the newline. If option
-r is used with -S default value, or when GNU extensions
are disabled, this condition is always met and references are completely
excluded from the output contexts.
-S regexp’--sentence-regexp=regexp’
This option selects which regular expression will describe the end of a
line or the end of a sentence. In fact, this regular expression is not
the only distinction between end of lines or end of sentences, and input
line boundaries have no special significance outside this option. By
default, when GNU extensions are enabled and if -r option is not
used, end of sentences are used. In this case, this regex is
imported from GNU Emacs:
[.?!][]\"')}]*\\($\\|\t\\| \\)[ \t\n]*
Whenever GNU extensions are disabled or if -r option is used, end
of lines are used; in this case, the default regexp is just:
\n
Using an empty regexp is equivalent to completely disabling end of
line or end of sentence recognition. In this case, the whole file is
considered to be a single big line or sentence. The user might want to
disallow all truncation flag generation as well, through option -F "". See Syntax of Regular Expressions in The GNU Emacs
Manual.
When the keywords happen to be near the beginning of the input line or sentence, this often creates an unused area at the beginning of the output context line; when the keywords happen to be near the end of the input line or sentence, this often creates an unused area at the end of the output context line. The program tries to fill those unused areas by wrapping around context in them; the tail of the input line or sentence is used to fill the unused area on the left of the output line; the head of the input line or sentence is used to fill the unused area on the right of the output line.
As a matter of convenience to the user, many usual backslashed escape
sequences from the C language are recognized and converted to the
corresponding characters by ptx itself.
-W regexp’--word-regexp=regexp’
This option selects which regular expression will describe each keyword.
By default, if GNU extensions are enabled, a word is a sequence of
letters; the regexp used is ‘\w+’. When GNU extensions are
disabled, a word is by default anything which ends with a space, a tab
or a newline; the regexp used is ‘[^ \t\n]+’.
An empty regexp is equivalent to not using this option.
See Syntax of Regular Expressions in The GNU Emacs
Manual.
As a matter of convenience to the user, many usual backslashed escape
sequences, as found in the C language, are recognized and converted to
the corresponding characters by ptx itself.
Next: Output formatting in ptx, Previous: Charset selection in ptx, Up: ptx invocation [Contents][Index]