Regex replacing hyphens in attributes name only - regex

I have a string that looks something like this.
<tag-name i-am-an-attribute="123" and-me-too="321">
All I want to do is replace the dashes into an underscore, but the tag-name should remain like it is.
Hope there are some regex guru's who can help me out.
[solution]
In case someone needs this.
I ended up with a perl oneliner command
echo '<tag-name i-am-an-attribute="123" and-me-too="321">' | perl -pe 's/( \K[^*"]*)-/$1_/g;' | perl -pe 's/ / /g;'
results in
<tag-name i_am_an_attribute="123" and_me_too="321">

Using sed:
sed ':l;s/-\([^- ]*\)\( *=\)/_\1\2/g;tl' input
Gives:
<tag-name i_am_an_attribute="123" and_me_too="321">

With <tag-name i-am-an-attribute="123" and-me-too="321"> as a line in a file:-
read -r < file
fullstring=$(echo "${REPLY}" | sed s'#-name #-name:#')
field1=$(echo "${fullstring}" | cut -d':' f1)
field2=$(echo "${fullstring}" | cut -d':' f2)
fixedfield=$(echo "${field2}" | sed s'#-#_#'g)
echo "${field1} ${fixedfield}"
I'm discovering that the most important thing, with scripting, is to provide yourself anchors within the text, that you can use to cut it up into segments that you can then perform operations on. Try to format your text as actual fields with seperators; it makes life a lot easier.

Related

how to regex replace before colon?

this is my original string:
NetworkManager/system connections/Wired 1.nmconnection:14 address1=10.1.10.71/24,10.1.10.1
I want to only add back slash to all the spaces before ':'
so, this is what I finally want:
NetworkManager/system\ connections/Wired\ 1.nmconnection:14 address1=10.1.10.71/24,10.1.10.1
I need to do this in bash, so, sed, awk, grep are all ok for me.
I have tried following sed, but none of them work
echo NetworkManager/system connections/Wired 1.nmconnection:14 address1=10.1.10.71/24,10.1.10.1 | sed 's/ .*\(:.*$\)/\\ .*\1/g'
echo NetworkManager/system connections/Wired 1.nmconnection:14 address1=10.1.10.71/24,10.1.10.1 | sed 's/\( \).*\(:.*$\)/\\ \1.*\2/g'
echo NetworkManager/system connections/Wired 1.nmconnection:14 address1=10.1.10.71/24,10.1.10.1 | sed 's/ .*\(:.*$\)/\\ \1/g'
echo NetworkManager/system connections/Wired 1.nmconnection:14 address1=10.1.10.71/24,10.1.10.1 | sed 's/\( \).*\(:.*$\)/\\ \1\2/g'
thanks for answering my question.
I am still quite newbie to stackoverflow, I don't know how to control the format in comment.
so, I just edit my original question
my real story is:
when I do grep or use cscope to search keyword, for example "address1" under /etc folder.
the result would be like:
./NetworkManager/system connections/Wired 1.nmconnection:14 address1=10.1.10.71/24,10.1.10.1
if I use vim to open file under cursor, suppose my vim cursor is now at word "NetworkManager",
then vim will understand it as
"./NetworkManager/system"
that's why I want to add "\" before space, so the search result would be more vim friendly:)
I did try to change cscope's source code, but very difficult to fully achieve this. so have to do a post replacement:(
If you only want to do the replacements if there is a : present in the string, you can check if there are at least 2 columns, setting the (output)field separator to a colon.
Data:
cat file michaelvandam#Michaels-MacBook-Pro
NetworkManager/system connections/Wired 1.nmconnection:14 address1=10.1.10.71/24,10.1.10.1
NetworkManager/system connections/Wired 1.nmconnection 14 address1=10.1.10.71/24,10.1.10.1%
Example in awk:
awk 'BEGIN {FS=OFS=":"}{if(NF>1)gsub(" ","\\ ",$1)}1' file
Output
NetworkManager/system\ connections/Wired\ 1.nmconnection:14 address1=10.1.10.71/24,10.1.10.1
NetworkManager/system connections/Wired 1.nmconnection 14 address1=10.1.10.71/24,10.1.10.1
This could be simply done in awk program, with your shown samples, please try following.
awk 'BEGIN{FS=OFS=":"} {gsub(/ /,"\\\\&",$1)} 1' Input_file
Explanation: Simple explanation would be, setting field separator and output field separator as : for this program. Then in main program using gsub(Global substitution) function of awk. Where substituting space with \ in 1st field only(as per OP's remarks it should be done before :) and printing line then.
An idea for a perl one liner in bash to use \G and \K (similar #CarySwoveland's comment).
perl -pe 's/\G[^ :]*\K /\\ /g' myfile
See this demo at tio.run or a pattern demo at regex101.
This might work for you (GNU sed):
sed -E ':a;s/^([^: ]*) /\1\n/;ta;s/\n/\\ /g' file
Replace spaces before : by newlines then replace newlines by \ 's.
Alternative using the hold space:
sed -E 's/:/\n:/;h;s/ /\\ /g;G;s/\n.*\n//' file
Split the line on the first :.
Amend the front section, remove the middle and append the unadulterated back section.
My answer is ugly and I think RavinderSingh13's answer is THE ONE, but I already took the time to write mine and it works (It's written step by step, but it's a one line command):
I got inspired by HatLess answer:
first get the text before the : with cut (I put the string in a file to make it easy to read, but this works on echo):
cut -d':' -f1 infile
Then replace spaces using sed:
cut -d':' -f1 infile | sed 's/\([a-z]\) /\1\\ /g'
Then echo the output with no new line:
echo -n "$(cut -d':' -f1 infile | sed -e 's/\([a-z]\) /\1\\ /g')"
Add the missing : and what comes after it:
echo -n "$(cut -d':' -f1 infile | sed -e 's/\([a-z]\) /\1\\ /g')" | cat - <(echo -n :) | cat - <(cut -d':' -f2 infile)

Why is sed not extracting value?

When I run my regex with sed
echo "abc-def-stg" | sed -e '/(\w*$)/g'
on regexr.com it works with no problems, but when I try to extract the value stg using said it does not work.
Can anyone explain why?
sed is used to replace strings. You are trying to extract.
Use (as John1024 said)
echo "abc-def-stg" | sed '/.*-//'
It will remove all up to and including the last hyphen. Or
echo "abc-def-stg" | grep -oE '[^-]+$'
It will extract all characters other than a hyphen at the end of the string.

sed - exchange words with delimiter

I'm trying swap words around with sed, not replace because that's what I keep finding on Google search.
I don't know if it's the regex that I'm getting wrong. I did a search for everything before a char and everything after a char, so that's how I got the regex.
echo xxx,aaa | sed -r 's/[^,]*/[^,]*$/'
or
echo xxx/aaa | sed -r 's/[^\/]*/[^\/]*$/'
I am getting this output:
[^,]*$,aaa
or this:
[^,/]*$/aaa
What am I doing wrong?
For the first sample, you should use:
echo xxx,aaa | sed 's/\([^,]*\),\([^,]*\)/\2,\1/'
For the second sample, simply use a character other than slash as the delimiter:
echo xxx/aaa | sed 's%\([^/]*\)/\([^/]*\)%\2/\1%'
You can also use \{1,\} to formally require one or more:
echo xxx,aaa | sed 's/\([^,]\{1,\}\),\([^,]\{1,\}\)/\2,\1/'
echo xxx/aaa | sed 's%\([^/]\{1,\}\)/\([^/]\{1,\}\)%\2/\1%'
This uses the most portable sed notation; it should work anywhere. With modern versions that support extended regular expressions (-r with GNU sed, -E with Mac OS X or BSD sed), you can lose some of the backslashes and use + in place of * which is more precisely what you're after (and parallels \{1,\} much more succinctly):
echo xxx,aaa | sed -E 's/([^,]+),([^,]+)/\2,\1/'
echo xxx/aaa | sed -E 's%([^/]+)/([^/]+)%\2/\1%'
With sed it would be:
sed 's#\([[:alpha:]]\+\)/\([[:alpha:]]\+\)#\2,\1#' <<< 'xxx/aaa'
which is simpler to read if you use extended posix regexes with -r:
sed -r 's#([[:alpha:]]+)/([[:alpha:]]+)#\2/\1#' <<< 'xxx/aaa'
I'm using two sub patterns ([[:alpha:]]+) which can contain one or more letters and are separated by a /. In the replacement part I reassemble them in reverse order \2/\1. Please also note that I'm using # instead of / as the delimiter for the s command since / is already the field delimiter in the input data. This saves us to escape the / in the regex.
Btw, you can also use awk for that, which is pretty easy to read:
awk -F'/' '{print $2,$1}' OFS='/' <<< 'xxx/aaa'

Sed : print all lines after match

I got my research result after using sed :
zcat file* | sed -e 's/.*text=\(.*\)status=[^/]*/\1/' | cut -f 1 - | grep "pattern"
But it only shows the part that I cut. How can I print all lines after a match ?
I'm using zcat so I cannot use awk.
Thanks.
Edited :
This is my log file :
[01/09/2015 00:00:47] INFO=54646486432154646 from=steve idfrom=55516654455457 to=jone idto=5552045646464 guid=100021623456461451463 n
um=6 text=hi my number is 0 811 22 1/12 status=new survstatus=new
My aim is to find all users that spam my site with their telephone numbers (using grep "pattern") then print all the lines to get all the information about each spam. The problem is there may be matches in INFO or id, so I use sed to get the text first.
Printing all lines after a match in sed:
$ sed -ne '/pattern/,$ p'
# alternatively, if you don't want to print the match:
$ sed -e '1,/pattern/ d'
Filtering lines when pattern matches between "text=" and "status=" can be done with a simple grep, no need for sed and cut:
$ grep 'text=.*pattern.* status='
You can use awk
awk '/pattern/,EOF'
n.b. don't be fooled: EOF is just an uninitialized variable, and by default 0 (false). So that condition cannot be satisfied until the end of file.
Perhaps this could be combined with all the previous answers using awk as well.
Maybe this is what you actually want? Find lines matching "pattern" and extract the field after text= up through just before status=?
zcat file* | sed -e '/pattern/s/.*text=\(.*\)status=[^/]*/\1/'
You are not revealing what pattern actually is -- if it's a variable, you cannot use single quotes around it.
Notice that \(.*\)status=[^/]* would match up through survstatus=new in your example. That is probably not what you want? There doesn't seem to be a status= followed by a slash anywhere -- you really should explain in more detail what you are actually trying to accomplish.
Your question title says "all line after a match" so perhaps you want everything after text=? Then that's simply
sed 's/.*text=//'
i.e. replace up through text= with nothing, and keep the rest. (I trust you can figure out how to change the surrounding script into zcat file* | sed '/pattern/s/.*text=//' ... oops, maybe my trust failed.)
The seldom used branch command will do this for you. Until you match, use n for next then branch to beginning. After match, use n to skip the matching line, then a loop copying the remaining lines.
cat file | sed -n -e ':start; /pattern/b match;n; b start; :match n; :copy; p; n ; b copy'
zcat file* | sed -e 's/.*text=\(.*\)status=[^/]*/\1/' | ***cut -f 1 - | grep "pattern"***
instead change the last 2 segments of your pipeline so that:
zcat file* | sed -e 's/.*text=\(.*\)status=[^/]*/\1/' | **awk '$1 ~ "pattern" {print $0}'**

bash script regex matching

In my bash script, I have an array of filenames like
files=( "site_hello.xml" "site_test.xml" "site_live.xml" )
I need to extract the characters between the underscore and the .xml extension so that I can loop through them for use in a function.
If this were python, I might use something like
re.match("site_(.*)\.xml")
and then extract the first matched group.
Unfortunately this project needs to be in bash, so -- How can I do this kind of thing in a bash script? I'm not very good with grep or sed or awk.
Something like the following should work
files2=(${files[#]#site_}) #Strip the leading site_ from each element
files3=(${files2[#]%.xml}) #Strip the trailing .xml
EDIT: After correcting those two typos, it does seem to work :)
xbraer#NO01601 ~
$ VAR=`echo "site_hello.xml" | sed -e 's/.*_\(.*\)\.xml/\1/g'`
xbraer#NO01601 ~
$ echo $VAR
hello
xbraer#NO01601 ~
$
Does this answer your question?
Just run the variables through sed in backticks (``)
I don't remember the array syntax in bash, but I guess you know that well enough yourself, if you're programming bash ;)
If it's unclear, dont hesitate to ask again. :)
I'd use cut to split the string.
for i in site_hello.xml site_test.xml site_live.xml; do echo $i | cut -d'.' -f1 | cut -d'_' -f2; done
This can also be done in awk:
for i in site_hello.xml site_test.xml site_live.xml; do echo $i | awk -F'.' '{print $1}' | awk -F'_' '{print $2}'; done
If you're using arrays, you probably should not be using bash.
A more appropriate example wold be
ls site_*.xml | sed 's/^site_//' | sed 's/\.xml$//'
This produces output consisting of the parts you wanted. Backtick or redirect as needed.