Using xargs perl to join lines

charissaf · Jul 10, 2007

Hello,
FreeBSD 4.10
#!/bin/ksh

I'm looking for some guidance on how to use a combination of grep and
xargs to find lines in multpile files beginning with > and append them
to the previous line.

For example, ideally I would like to use:

grep -r -l '^>' . | xargs perl -pi -e :a -e '$!N;s/\n>/>/;ta' -e 'P;D'

I am basing this one liner on the following sed example:

# if a line begins with an equal sign, append it to the previous line
# and replace the "=" with a single space
# sed -e :a -e '$!N;s/\n=/ /;ta' -e 'P;D'

The error I receive is: N: Event not found.

A sample file would have a line similar to
<htm
The ideal result is to bring the closing > up to the preceeding line:
<htm>

Please look at my syntax or let me know if there is another way of
doing this operation using xargs perl.

Thank you!
C

charissaf · Jul 10, 2007

Hello,
FreeBSD 4.10
#!/bin/ksh

I'm looking for some guidance on how to use a combination of grep and
xargs to find lines in multpile files beginning with > and append them
to the previous line.

For example, ideally I would like to use:

grep -r -l '^>' . | xargs perl -pi -e :a -e '$!N;s/\n>/>/;ta' -e 'P;D'

I am basing this one liner on the following sed example:

# if a line begins with an equal sign, append it to the previous line
# and replace the "=" with a single space
# sed -e :a -e '$!N;s/\n=/ /;ta' -e 'P;D'

The error I receive is: N: Event not found.

A sample file would have a line similar to
<htm

The ideal result is to bring the closing > up to the preceeding line:
<htm>

Please look at my syntax or let me know if there is another way of
doing this operation using xargs perl.

Thank you!
C

More info:
sample file has
<htm
Also, I turned on the perl -w option and have the following info:
Bareword found where operator expected at -e line 2, near "$!N"
(Missing operator before N?)
Can't call method "a" without a package or object reference at -e line
1, <> chunk 1.

John W. Krahn · Jul 10, 2007

Hello,
FreeBSD 4.10
#!/bin/ksh

I'm looking for some guidance on how to use a combination of grep and
xargs to find lines in multpile files beginning with > and append them
to the previous line.

For example, ideally I would like to use:

grep -r -l '^>' . | xargs perl -pi -e :a -e '$!N;s/\n>/>/;ta' -e 'P;D'

I am basing this one liner on the following sed example:

# if a line begins with an equal sign, append it to the previous line
# and replace the "=" with a single space
# sed -e :a -e '$!N;s/\n=/ /;ta' -e 'P;D'

The error I receive is: N: Event not found.

Of course Perl cannot run sed code just as sed cannot run Python code.

A sample file would have a line similar to
<htm

The ideal result is to bring the closing > up to the preceeding line:
<htm>

Please look at my syntax or let me know if there is another way of
doing this operation using xargs perl.

$ echo "
<html

" | perl -076pe's/\s+>$/>/'

<html>

John

charissaf · Jul 10, 2007

Of course Perl cannot runsedcode just assedcannot run Python code.

$ echo "
<html

" | perl -076pe's/\s+>$/>/'

<html>

John
--
Perl isn't a toolbox, but a small machine shop where you
can special-order certain sorts of tools at low cost and
in short order. -- Larry Wall- Hide quoted text -

- Show quoted text -

Wow, thank you for your help!

Clenna Lumina · Jul 12, 2007

Joe said:
Are you aware that some shells require ! to be quoted as \! even
inside ''? -Joe

My bash shell doesn't treat ! as special when in single quotes.
Otherwise, it acts as a histoy shortcut:

$ echo 12345
12345
$ echo 123
123
$ echo ABC
ABC
$ history | tail -n 4 | head -n 3
25767 echo 12345
25768 echo 123
25769 echo ABC
$ perl -e 'print "[", shift, "]\n";' "!25767"
perl -e 'print "[", shift, "]\n";' "echo 12345"
[echo 12345]
$ perl -e 'print "[", shift, "]\n";' !25767
perl -e 'print "[", shift, "]\n";' echo 12345
[echo]
$ perl -e 'print "[", shift, "]\n";' '!25767'
[!25767]
$ perl -e 'print "[", shift, "]\n";' \!25767
[!25767]
$ echo $SHELL
/bin/bash
$ bash --version
GNU bash, version 2.05a.0(1)-release (i686-pc-linux-gnu) ...

Howver, I checked with tcsh, and it doesn't seem to care if it's single
quoted or not (kinda odd?)

$ echo 123
123
$ echo 456
456
$ echo 789
789
$ history | tail -n 4 | head -n 3
2 9:27 echo 123
3 9:27 echo 456
4 9:27 echo 789
$ perl -e 'print "[", shift, "]\n";' "!3"
perl -e 'print "[", shift, "]\n";' "echo 456"
[echo 456]
$ perl -e 'print "[", shift, "]\n";' '!3'
perl -e 'print "[", shift, "]\n";' 'echo 456'
[echo 456]
$ perl -e 'print "[", shift, "]\n";' '\!3'
[!3]
$ echo $version
tcsh 6.10.00 (Astron) 2000-11-19 (i386-intel-linux) ...

I thought all shells are not supposed regard single quoted characters as
special?

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Using xargs perl to join lines

charissaf

charissaf

John W. Krahn

charissaf

Clenna Lumina

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