Fix typo in pcre2grep documentation.
This commit is contained in:
Philip.Hazel
parent
784b3d2409
commit
afa3c56afd
|
|
@ -22,11 +22,12 @@ please consult the man page, in case the conversion went wrong.
|
|||
<li><a name="TOC7" href="#SEC7">NEWLINES</a>
|
||||
<li><a name="TOC8" href="#SEC8">OPTIONS COMPATIBILITY</a>
|
||||
<li><a name="TOC9" href="#SEC9">OPTIONS WITH DATA</a>
|
||||
<li><a name="TOC10" href="#SEC10">MATCHING ERRORS</a>
|
||||
<li><a name="TOC11" href="#SEC11">DIAGNOSTICS</a>
|
||||
<li><a name="TOC12" href="#SEC12">SEE ALSO</a>
|
||||
<li><a name="TOC13" href="#SEC13">AUTHOR</a>
|
||||
<li><a name="TOC14" href="#SEC14">REVISION</a>
|
||||
<li><a name="TOC10" href="#SEC10">CALLING EXTERNAL SCRIPTS</a>
|
||||
<li><a name="TOC11" href="#SEC11">MATCHING ERRORS</a>
|
||||
<li><a name="TOC12" href="#SEC12">DIAGNOSTICS</a>
|
||||
<li><a name="TOC13" href="#SEC13">SEE ALSO</a>
|
||||
<li><a name="TOC14" href="#SEC14">AUTHOR</a>
|
||||
<li><a name="TOC15" href="#SEC15">REVISION</a>
|
||||
</ul>
|
||||
<br><a name="SEC1" href="#TOC1">SYNOPSIS</a><br>
|
||||
<P>
|
||||
|
|
@ -735,7 +736,57 @@ The exceptions to the above are the <b>--colour</b> (or <b>--color</b>) and
|
|||
options does have data, it must be given in the first form, using an equals
|
||||
character. Otherwise <b>pcre2grep</b> will assume that it has no data.
|
||||
</P>
|
||||
<br><a name="SEC10" href="#TOC1">MATCHING ERRORS</a><br>
|
||||
<br><a name="SEC10" href="#TOC1">CALLING EXTERNAL SCRIPTS</a><br>
|
||||
<P>
|
||||
On non-Windows systems, <b>pcre2grep</b> has, by default, support for calling
|
||||
external programs or scripts during matching by making use of PCRE2's callout
|
||||
facility. However, this support can be disabled when <b>pcre2grep</b> is built.
|
||||
You can find out whether your binary has support for callouts by running it
|
||||
with the <b>--help</b> option. If the support is not enabled, all callouts in
|
||||
patterns are ignored by <b>pcre2grep</b>.
|
||||
</P>
|
||||
<P>
|
||||
A callout in a PCRE2 pattern is of the form (?C<arg>) where the argument is
|
||||
either a number or a quoted string (see the
|
||||
<a href="pcre2callout.html"><b>pcre2callout</b></a>
|
||||
documentation for details). Numbered callouts are ignored by <b>pcre2grep</b>.
|
||||
String arguments are parsed as a list of substrings separated by pipe (vertical
|
||||
bar) characters. The first substring must be an executable name, with the
|
||||
following substrings specifying arguments:
|
||||
<pre>
|
||||
executable_name|arg1|arg2|...
|
||||
</pre>
|
||||
Any substring (including the executable name) may contain escape sequences
|
||||
started by a dollar character: $<digits> or ${<digits>} is replaced by the
|
||||
captured substring of the given decimal number, which must be greater than
|
||||
zero. If the number is greater than the number of capturing substrings, or if
|
||||
the capture is unset, the replacement is empty.
|
||||
</P>
|
||||
<P>
|
||||
Any other character is substituted by itself. In particular, $$ is replaced by
|
||||
a single dollar and $| is replaced by a pipe character. Here is an example:
|
||||
<pre>
|
||||
echo -e "abcde\n12345" | pcre2grep \
|
||||
'(?x)(.)(..(.))
|
||||
(?C"/bin/echo|Arg1: [$1] [$2] [$3]|Arg2: $|${1}$| ($4)")()' -
|
||||
|
||||
Output:
|
||||
|
||||
Arg1: [a] [bcd] [d] Arg2: |a| ()
|
||||
abcde
|
||||
Arg1: [1] [234] [4] Arg2: |1| ()
|
||||
12345
|
||||
</pre>
|
||||
The parameters for the <b>execv()</b> system call that is used to run the
|
||||
program or script are zero-terminated strings. This means that binary zero
|
||||
characters in the callout argument will cause premature termination of their
|
||||
substrings, and therefore should not be present. Any syntax errors in the
|
||||
string (for example, a dollar not followed by another character) cause the
|
||||
callout to be ignored. If running the program fails for any reason (including
|
||||
the non-existence of the executable), a local matching failure occurs and the
|
||||
matcher backtracks in the normal way.
|
||||
</P>
|
||||
<br><a name="SEC11" href="#TOC1">MATCHING ERRORS</a><br>
|
||||
<P>
|
||||
It is possible to supply a regular expression that takes a very long time to
|
||||
fail to match certain lines. Such patterns normally involve nested indefinite
|
||||
|
|
@ -751,7 +802,7 @@ overall resource limit; there is a second option called <b>--recursion-limit</b>
|
|||
that sets a limit on the amount of memory (usually stack) that is used (see the
|
||||
discussion of these options above).
|
||||
</P>
|
||||
<br><a name="SEC11" href="#TOC1">DIAGNOSTICS</a><br>
|
||||
<br><a name="SEC12" href="#TOC1">DIAGNOSTICS</a><br>
|
||||
<P>
|
||||
Exit status is 0 if any matches were found, 1 if no matches were found, and 2
|
||||
for syntax errors, overlong lines, non-existent or inaccessible files (even if
|
||||
|
|
@ -759,11 +810,11 @@ matches were found in other files) or too many matching errors. Using the
|
|||
<b>-s</b> option to suppress error messages about inaccessible files does not
|
||||
affect the return code.
|
||||
</P>
|
||||
<br><a name="SEC12" href="#TOC1">SEE ALSO</a><br>
|
||||
<br><a name="SEC13" href="#TOC1">SEE ALSO</a><br>
|
||||
<P>
|
||||
<b>pcre2pattern</b>(3), <b>pcre2syntax</b>(3).
|
||||
<b>pcre2pattern</b>(3), <b>pcre2syntax</b>(3), <b>pcre2callout</b>(3).
|
||||
</P>
|
||||
<br><a name="SEC13" href="#TOC1">AUTHOR</a><br>
|
||||
<br><a name="SEC14" href="#TOC1">AUTHOR</a><br>
|
||||
<P>
|
||||
Philip Hazel
|
||||
<br>
|
||||
|
|
@ -772,11 +823,11 @@ University Computing Service
|
|||
Cambridge, England.
|
||||
<br>
|
||||
</P>
|
||||
<br><a name="SEC14" href="#TOC1">REVISION</a><br>
|
||||
<br><a name="SEC15" href="#TOC1">REVISION</a><br>
|
||||
<P>
|
||||
Last updated: 03 January 2015
|
||||
Last updated: 06 April 2016
|
||||
<br>
|
||||
Copyright © 1997-2015 University of Cambridge.
|
||||
Copyright © 1997-2016 University of Cambridge.
|
||||
<br>
|
||||
<p>
|
||||
Return to the <a href="index.html">PCRE2 index page</a>.
|
||||
|
|
|
|||
|
|
@ -687,9 +687,9 @@ a single dollar and $| is replaced by a pipe character. Here is an example:
|
|||
echo -e "abcde\en12345" | pcre2grep \e
|
||||
'(?x)(.)(..(.))
|
||||
(?C"/bin/echo|Arg1: [$1] [$2] [$3]|Arg2: $|${1}$| ($4)")()' -
|
||||
|
||||
.sp
|
||||
Output:
|
||||
|
||||
.sp
|
||||
Arg1: [a] [bcd] [d] Arg2: |a| ()
|
||||
abcde
|
||||
Arg1: [1] [234] [4] Arg2: |1| ()
|
||||
|
|
|
|||
|
|
@ -725,6 +725,57 @@ OPTIONS WITH DATA
|
|||
equals character. Otherwise pcre2grep will assume that it has no data.
|
||||
|
||||
|
||||
CALLING EXTERNAL SCRIPTS
|
||||
|
||||
On non-Windows systems, pcre2grep has, by default, support for calling
|
||||
external programs or scripts during matching by making use of PCRE2's
|
||||
callout facility. However, this support can be disabled when pcre2grep
|
||||
is built. You can find out whether your binary has support for call-
|
||||
outs by running it with the --help option. If the support is not
|
||||
enabled, all callouts in patterns are ignored by pcre2grep.
|
||||
|
||||
A callout in a PCRE2 pattern is of the form (?C<arg>) where the argu-
|
||||
ment is either a number or a quoted string (see the pcre2callout docu-
|
||||
mentation for details). Numbered callouts are ignored by pcre2grep.
|
||||
String arguments are parsed as a list of substrings separated by pipe
|
||||
(vertical bar) characters. The first substring must be an executable
|
||||
name, with the following substrings specifying arguments:
|
||||
|
||||
executable_name|arg1|arg2|...
|
||||
|
||||
Any substring (including the executable name) may contain escape
|
||||
sequences started by a dollar character: $<digits> or ${<digits>} is
|
||||
replaced by the captured substring of the given decimal number, which
|
||||
must be greater than zero. If the number is greater than the number of
|
||||
capturing substrings, or if the capture is unset, the replacement is
|
||||
empty.
|
||||
|
||||
Any other character is substituted by itself. In particular, $$ is
|
||||
replaced by a single dollar and $| is replaced by a pipe character.
|
||||
Here is an example:
|
||||
|
||||
echo -e "abcde\n12345" | pcre2grep \
|
||||
'(?x)(.)(..(.))
|
||||
(?C"/bin/echo|Arg1: [$1] [$2] [$3]|Arg2: $|${1}$| ($4)")()' -
|
||||
|
||||
Output:
|
||||
|
||||
Arg1: [a] [bcd] [d] Arg2: |a| ()
|
||||
abcde
|
||||
Arg1: [1] [234] [4] Arg2: |1| ()
|
||||
12345
|
||||
|
||||
The parameters for the execv() system call that is used to run the pro-
|
||||
gram or script are zero-terminated strings. This means that binary zero
|
||||
characters in the callout argument will cause premature termination of
|
||||
their substrings, and therefore should not be present. Any syntax
|
||||
errors in the string (for example, a dollar not followed by another
|
||||
character) cause the callout to be ignored. If running the program
|
||||
fails for any reason (including the non-existence of the executable), a
|
||||
local matching failure occurs and the matcher backtracks in the normal
|
||||
way.
|
||||
|
||||
|
||||
MATCHING ERRORS
|
||||
|
||||
It is possible to supply a regular expression that takes a very long
|
||||
|
|
@ -753,7 +804,7 @@ DIAGNOSTICS
|
|||
|
||||
SEE ALSO
|
||||
|
||||
pcre2pattern(3), pcre2syntax(3).
|
||||
pcre2pattern(3), pcre2syntax(3), pcre2callout(3).
|
||||
|
||||
|
||||
AUTHOR
|
||||
|
|
@ -765,5 +816,5 @@ AUTHOR
|
|||
|
||||
REVISION
|
||||
|
||||
Last updated: 03 January 2015
|
||||
Copyright (c) 1997-2015 University of Cambridge.
|
||||
Last updated: 06 April 2016
|
||||
Copyright (c) 1997-2016 University of Cambridge.
|
||||
|
|
|
|||
Loading…
Reference in New Issue