Removing special chars from line

ataX has asked for the wisdom of the Perl Monks concerning the following question:

Hi monks, i have a file that i need to parse, this file comes from the output of a DSLAM command.

When i open the file i find some weird chars (-^[[1D\^[[1D|^[[1D/^) on it, that i need to remove in order to better parse the file

this is the part of the file that has the special chars:

configure qos profiles cac FD_ONTUniVideo res-voice-bandwidth 0 max-mc
+ast-bandwidth 24000 res-data-bandwidth 0
configure qos profiles marker d1p marker_hsi default-dot1p 2
configure qos profiles marker d1p FD_Marker_BE default-dot1p 0
configure qos profiles marker d1p FD_Marker_CL default-dot1p 3
configure qos profiles marker d1p FD_Marker_Voice default-dot1p 6
-^[[1D\^[[1D|^[[1D/^[[1D-^[[1D\^[[1D|^[[1D/^[[1D-^[[1D\^[[1D|^[[1D/^[[
+1D-^[[1D\^[[1D|^[[1D/^[[1D-^[[1D\^[[1D|^[[1D/^[[1D-^[[1D\^[[1D|^[[1D/
+^[[1D-^[[1D\^[[1D|^[[1D/^[[1D-^[[1D\^[[1D|^[[1D/^[[1D-^[[1D\^[[1D|^[[
+1D/^[[1D-^[[1D\^[[1D|^[[1D/^[[1D-^[[1D\^[[1D|^[[1D/^[[1D-^[[1D\^[[1D|
+^[[1D/^[[1D-^[[1D\^[[1D|^[[1D/^[[1D-^[[1D\^[[1D|^[[1D/^[[1D-^[[1D\^[[
+1D|^[[1D/^[[1D-^[[1D\^[[1D|^[[1D/^[[1D-^[[1D\^[[1D|^[[1D/^[[1D-^[[1D\
+^[[1D|^[[1D/^[[1D-^[[1D\^[[1D|^[[1D/^[[1D-^[[1D\^[[1D|^[[1D/^[[1D-^[[
+1D\^[[1D|^[[1D/^[[1D-^[[1D\^[[1D|^[[1D/^[[1D-^[[1D\^[[1D|^[[1D/^[[1D-
+^[[1D\^[[1D|^[[1D/^[[1D-^[[1D\^[[1D|^[[1D/^[[1D ^[[1Dconfigure qos pr
+ofiles policer Flash1d committed-info-rate 640 committed-burst-size 1
+14000
configure qos profiles policer Flash1u committed-info-rate 320 committ
+ed-burst-size 114000
configure qos profiles policer Flash2d committed-info-rate 928 committ
+ed-burst-size 114000
configure qos profiles policer Flash2u committed-info-rate 320 committ
+ed-burst-size 114000
configure qos profiles policer Flash3d committed-info-rate 1280 commit
+ted-burst-size 114000
configure qos profiles policer Flash3u committed-info-rate 320 committ
+ed-burst-size 114000
configure qos profiles policer Flash4d committed-info-rate 1824 commit
+ted-burst-size 114000
configure qos profiles policer Flash4u committed-info-rate 320 committ
+ed-burst-size 114000
configure qos profiles policer p-neg2d committed-info-rate 480 committ
+ed-burst-size 114000
configure qos profiles policer p-neg2u committed-info-rate 480 committ
+ed-burst-size 114000
configure qos profiles policer p-neg4d committed-info-rate 640 committ
+ed-burst-size 114000
configure qos profiles policer p-neg4u committed-info-rate 640 committ
+ed-burst-size 114000
configure qos profiles policer p-neg6d committed-info-rate 1824 commit
+ted-burst-size 114000
configure qos profiles policer p-neg6u committed-info-rate 1824 commit
+ted-burst-size 114000
configure qos profiles policer p-res2d committed-info-rate 480 committ
+ed-burst-size 114000
configure qos profiles policer p-res2u committed-info-rate 480 committ
+ed-burst-size 114000
configure qos profiles policer Flash_5d committed-info-rate 320 commit
+ted-burst-size 114000
[download]

Now this is a snip of my perl code that parses the file and i can't seem to find a way to strip those special chars from the file

 use strict;
use warnings;
use IO::File;

my $qosProfLog = "/svn/projects/DSLAMCheck/branches/fullcheck+multipro
+cess/work/qosprofile/qosprofilelist_log_ACST8H1-11283.log";
my $QOSPROFLIST_LOG_FH = IO::File->new();
$QOSPROFLIST_LOG_FH->open($qosProfLog,"r");

while (<$QOSPROFLIST_LOG_FH>) {

                    if ( /configure qos profiles policer/ ) {
                    chomp;
                    tr/\040-\176//csd;
                    print "$_\n";
                    }
}
[download]

Thanks for your help.

Comment on Removing special chars from line Select or Download Code

Replies are listed 'Best First'.
Re: Removing special chars from line by jwkrahn (Abbot) on Oct 17, 2011 at 20:47 UTC
`tr/\040-\176//csd;` [download] You can't use all three options with `tr///` at the same time. It looks like you only need: `tr/\040-\176//cd;` [download]	[reply] [d/l] [select]
Re^2: Removing special chars from line by ataX (Initiate) on Oct 18, 2011 at 14:41 UTC
I removed the s parameter from tr but the unprintables are still there. is there a way to remove all non-printable chars and keep the whitespace at the same time?	[reply]
Re^3: Removing special chars from line by graff (Chancellor) on Oct 19, 2011 at 01:44 UTC
It looks like the stream of characters that you want to remove are all cases of "backspace" (expressed as a four-character sequence 'esc [ 1 D', but with the 'esc' character transliterated by your terminal window display into two printable characters: "^" and "[" ), followed by one of: `/ - \ \|` It's the ascii-art version of the rotating clock-hand. To get rid of that specific pattern, use a regex substitution -- I think it would go something like this (not tested): `s{ (?: \e \[ 1 D [\\/\|-] )+ }{}gx;` [download] The "\e" represents the escape character, the open-square-bracket needs to be preceded by backslash to be treated as a literal character, and the four "rotating hand" characters are in a character class that follows "D" (the hyphen needs to be either last or first in the class list, to avoid being interpreted as a range operator, and the backslash needs to be escaped, but "\|" does not (and neither does "/", since I'm not using that as the regex delimiter).	[reply] [d/l] [select]