Using sed to replace <? with <?php - regex

I'm trying to programmatically replace <? with <?php in a bunch of file, but my sed regex isn't behaving like I expected. Can you tell me what's wrong with it?
I'm testing it on the command line here:
$ sed -e 's/<\?/<\?php/g'
<?
<?php?<?php
d
<?phpd<?php


I don't think you need the escapes on the ?:
sed -e 's/<?/<?php/g'


You don't need to escape the back reference in the replacement.
sed 's#<\?#<?php#'
In a pipe, to correct for doubling the php:
sed 's#<\?#<?php#g' | sed 's#phpphp#php#g'


Do you really have to use sed, or can you use perl as well?
perl -pi.tmp -e 's,^<\?(?!php),<?php,' *.php *.inc
rm *.tmp
I am using a negative look-ahead to avoid generating <?phpphp in cases where the files already start with the correct characters.


This will also skip matching with <?=$variable:
sed -e 's/<?\([^=p]\)/<?php\1/g' -e 's/<?$/<?php/g'

Related

Swap columns in bash using SED without using loop

I'm new to Sed, I'm trying to learn some pattern using Sed.
I got a filenamne.txt that has the following entry:
ppp/jjj qqq/kkk rrr/lll
My goal is to swap the word before the slash and the word after the slash in each of the three word1/word2 columns:
jjj/ppp kkk/qqq lll/rrr
I tried using sed –re ‘s!(.*)(/)(.*)!\1\2\!’ filename.txt, but it didn't work. Any idea how can I go about it?

$ echo "ppp/jjj qqq/kkk rrr/lll" | sed -e 's/$/ /' -e 's!\([^/]*\)/\([^ ]*\) !\2/\1 !g'
jjj/ppp kkk/qqq lll/rrr

Use replacement in perl command-line is a lot more straight-forward :-
perl -pe 's/(\w+)\/(\w+)/$2\/$1/g' file
jjj/ppp kkk/qqq lll/rrr

$ sed 's#\([^ ]*\)/\([^ ]*\)#\2/\1#g' file
jjj/ppp kkk/qqq lll/rrr

BASH: replacing PERL with SED for in-place substitution

Would like to replace this statement with perl:
perl -pe "s|(?<=://).+?(?=/)|$2:80|"
with
sed -e "s|<regex>|$2:80|"
Since sed has a much less powerful regex engine (for example it does not support look-arounds) the task boils down to writing a sed compatible regex to match only a domain name in a fully qualitied URL. Examples:
http://php2-mindaugasb.c9.io/Testing/JS/displayName.js
http://php2-mindaugasb.c9.io?a=Testing.js
http://www.google.com?a=Testing.js
Should become:
http://$2:80/Testing/JS/displayName.js
http://$2:80?a=Testing.js
http://$2:80?a=Testing.js
A solution like this would be ok:
sed -e "s|<regex>|http://$2:80|"
Thanks :)

Use the below sed command.
$ sed "s~//[^/?]\+\([?/]\)~//\$2:80\1~g" file
http://$2:80/Testing/JS/displayName.js
http://$2:80?a=Testing.js
http://$2:80?a=Testing.js
You must need to escape the $ at the replacement part.

sed 's|http://[^/?]*|http://$2:80|' file
Output:
http://$2:80/Testing/JS/displayName.js
http://$2:80?a=Testing.js
http://$2:80?a=Testing.js

Using sed to replace IP using regex

Assuming a simple text file:
123.123.123.123
I would like to replace the IP inside of it with 222.222.222.222. I have tried the below but nothing changes, however the same regex seems to work in this Regexr
sed -i '' 's/(\d{1,3}\.){3}\d{1,3}/222.222.222.222/' file.txt
Am I missing something?

Two problems here:
sed doesn't like PCRE digit property \d, use range: [0-9] or POSIX [[:digit:]]
You need to use -r flag for extended regex as well.
This should work:
s='123.123.123.123'
sed -r 's/([0-9]{1,3}\.){3}[0-9]{1,3}/222.222.222.222/' <<< "$s"
222.222.222.222
Better would be to use anchors to avoid matching unexpected input:
sed -r 's/^([0-9]{1,3}\.){3}[0-9]{1,3}$/222.222.222.222/' <<< "$s"
PS: On OSX use -E instead of -r:
sed -E 's/^([0-9]{1,3}\.){3}[0-9]{1,3}$/222.222.222.222/' <<< "$s"
222.222.222.222

You'd better use -r, as indicated by anubhava.
But in case you don't have it, you have to escape every single (, ), { and }. And also, use [0-9] instead of \d:
$ sed 's/\([0-9]\{1,3\}\.\)\{3\}[0-9]\{1,3\}/222.222.222.222/' <<< "123.123.123.123"
222.222.222.222

sed plus sign doesn't work

I'm trying to replace /./ or /././ or /./././ to / only in bash script. I've managed to create regex for sed but it doesn't work.
variable="something/./././"
variable=$(echo $variable | sed "s/\/(\.\/)+/\//g")
echo $variable # this should output "something/"
When I tried to replace only /./ substring it worked with regex in sed \/\.\/. Does sed regex requires more flags to use multiplication of substring with + or *?

Use -r option to make sed to use extended regular expression:
$ variable="something/./././"
$ echo $variable | sed -r "s/\/(\.\/)+/\//g"
something/

Any sed:
sed 's|/\(\./\)\{1,\}|/|g'
But a + or \{1,\} would not even be required in this case, a * would do nicely, so
sed 's|/\(\./\)*|/|g'
should suffice

Two things to make it simple:
$ variable="something/./././"
$ sed -r 's#(\./){1,}##' <<< "$variable"
something/
Use {1,} to indicate one or more patterns. You won't need g with this.
Use different delimiterers # in above case to make it readable
+ is ERE so you need to enable -E or -r option to use it

You can also do this with bash's built-in parameter substitution. This doesn't require sed, which doesn't accept -r on a Mac under OS X:
variable="something/./././"
a=${variable/\/*/}/ # Remove slash and everything after it, then re-apply slash afterwards
echo $a
something/
See here for explanation and other examples.

Regex matching using SED in bash

I want to match the following line with the regex in sed:
db=connect_str=DBI:SQLAnywhere:ENG=ABC1_hostname12;DBN=ABC12;UID=USERID;PWD=passwd123;LINKS=tcpip{host=10.11.12.13:1234}
The regex I am using is:
sed -n '/ABC1_.+;/p' Config/db_conn.cfg
but this does not work. On the other hand, it works if I use:
sed -n '/ABC1_.*;/p' Config/db_conn.cfg
Can someone please explain why it's not working? Also is there another way to match it?

It's because sed is basic regex by default, which needs + to be escaped or else it represents a literal + instead of a regex +:
sed -n '/ABC1_.\+;/p' Config/db_conn.cfg
To use regex you're familiar with try sed -r -n (extended regex) and then you can do:
sed -r -n '/ABC1_.+;/p' Config/db_conn.cfg