So I think I've cracked the regex but just can't crack how to get sed to make the changes. I have a variable which is this:
MAKEVAR = EPICS_BASE=$CI_PROJECT_DIR/3.16/base IPAC=$CI_PROJECT_DIR/3.16/support/ipac SNCSEQ=$CI_PROJECT_DIR/3.16/support/seq
(All one line). But I want to delete the particular section defining IPAC so my regex looks like this:
(IPAC.+\s)
I know from using this tool that that should be correct:
https://www.regextester.com/98103
However when I run different iterations of trying out sed like:
sed 's/(IPAC.+\s)/\&/g' <<< "$MAKEVAR"
And then echo out MAKEVAR, the IPAC section still exists.
How can I update a particular section of text in a shell variable to remove a section beginning with IPAC up until the next space?
Thanks in advance
regextester (or any other online tool) is a great way to verify that a regexp works in that online tool. Unfortunately that doesn't mean it'll work in any given command-line tool. In particular your regexp includes \s which is specific to PCREs and some GNU tools, and uses (...) to delineate capture groups but that's only used in EREs and PCREs, not BREs such as sed supports by default where you'd have to use \(...\), and your replacement text is using '&' which is telling sed you want to replace the string that matches the regexp with a literal \& when in fact you just want to remove it.
This is how to do what I think you're trying to do using any sed:
$ sed 's/IPAC[^ ]* //' <<< "$MAKEVAR"
EPICS_BASE=$CI_PROJECT_DIR/3.16/base SNCSEQ=$CI_PROJECT_DIR/3.16/support/seq
Nevermind, found a workaround:
MAKEVAR=$(sed -E 's/(IPAC.+ipac)//' <<<"$MAKEVAR")
Use a shorter
MAKEVAR=$(sed 's/IPAC.*ipac//' <<< "$MAKEVAR")
IPAC.*ipac matches all the way from first IPAC to last ipac. The matched text is removed from the text.
Related
I have a java properties file that looks like the following:
SiteUrlEndpoint=google.com/mySite
I want to use sed -i to inline replace the url but keep the context path that comes out of it. So for example if I wanted to change the properties file above to use amazon.com then the result would look like:
SiteUrlEndpoint=amazon.com/mySite
I am having trouble with sed to only replace the url and keeping the context path when replacing it inline.
My attempt:
sed -i 's:^[ \t]*siteUrlEndpoint[ \t]*=\([ \t]*.*\)[/]*$:siteUrlEndpoint = 'amazon.com':' file
You can do it with two backreferences, e.g.
sed -i.bak 's|^\(SiteUrlEndpoint=\).*/\(.*\)|\1amazon.com/\2|' file
note: the match of text up to / is greedy. If you have multiple parts of the path following the domain, you probably want to preserve all path components. To make it non-greedy, you could use the following instead
sed -i.bak 's|^\(SiteUrlEndpoint=\)[^/]*/\(.*\)|\1amazon.com/\2|' file
(you can add i.bak to create a backup of the original in file.bak)
To accomplish the same thing, you can match SiteUrlEndpoint= at the beginning of the line first, and then use a single backreference for the change, e.g.
sed -i.bak '/^SiteUrlEndpoint=/s|=[^/]*\(/.*\)|=amazon.com\1|' file
For example, given a file sites containing:
$ cat sites
SiteUrlEndpoint=google.com/path/to/mySite
SiteUrlSomeOther=google.com/mySite
You can change google.com to amazon.com with (using non-greedy form of first example):
$ sed -i 's|^\(SiteUrlEndpoint=\)[^/]*/\(.*\)|\1amazon.com/\2|' sites
Confirming:
$ cat sites
SiteUrlEndpoint=amazon.com/path/to/mySite
SiteUrlSomeOther=google.com/mySite
and
$ cat sites.bak
SiteUrlEndpoint=google.com/path/to/mySite
SiteUrlSomeOther=google.com/mySite
Explanation (first form)
sed -i.bak 's|^\(SiteUrlEndpoint=\) - locate & save
SiteUrlEndpoint=
[^/]*/ - match any folowing characters up to first / (non-greedy -
adjust as needed)
\(.*\) - match and save anything following /
|\1amazon.com/\2|' - full replacement (explanation below)
\1 - first back-reference containing SiteUrlEndpoint=
amazon.com - self-explanatory
/\2 - the '/' second back-reference of everything that followed.
Look over all the solutions and let me know if you have questions.
Regular expressions are hard, especially with complex regular expressions and/or large input files where unexpected changes are to be avoided.
Therefore I strongly recommend using sed -i.bak to keep a backup of the original file to then run a diff on both of them to see what changed.
Assuming that
You only want to change things after the tag siteUrlEndpoint (case insensitive)
You want to change the URL to amazon.com while leaving the path intact
I came up with this solution:
sed -i.bak 's;^\([ \t]*siteurlendpoint[ \t]*=[ \t]*\)[^/]*\(.*\);\1amazon.com\2;Ig' infile
I used a semicolon instead of your colon, that's just my preference when I don't want to use / ;)
Then I wrapped both the leading white spaces and siteurlendpoint as well as everything from the first / onwards into brackets \( \) so that I can take them again in the replacement with \1 and \2. That way I keep the indentation and the capitalisation of SiteUrlEndpoint intact.
For the search options I added an I to the g to make the search case insensitive. I am not sure how standard this option is, you might have to see whether your sed understands it.
The actual part that I want to replace I have just any character not including the next /: [^/]*
As for your line:
Your search term only searches for siteUrlEndpoint with lower case s. Since in your examples you wrote it with capital S, it wouldn't have triggered.
The final [/]*$ doesn't make any sense at all. "This line can end in zero or more of any of these caracters: /."
You precede this [/]*$ with .* which means: zero or more of any character at all.
The single quotes around 'amazon.com' might interfere with the single quotes around the whole search/replace term. It seems to work, but it is sloppy, and will fail if there are ever any spaces in there. It doesn't seem to serve any purpose anyway (except if you want to replace amazon.com with some environment variable like $NEWSITE) so I don't know why you're doing that.
Keep a backreference to the part just before the domain - then match and replace the domain - you can add the -i option after verifying the output of the sed command
url=amazon.com
sed -r 's/\b(SiteUrlEndpoint\s*=\s*)[^/]+/\1'$url'/'
Keep it simple:
$ sed -E 's/(SiteUrlEndpoint=)[^.]+/\1amazon/' file
SiteUrlEndpoint=amazon.com/mySite
I have a file with the following entries:
folder1/a_b.csv folder1/generated/
folder2/folder3/a_b1.csv folder12/generated/
folder4/b_c.csv folder123/generated/
folder5/d.csv folder1/new_folder/generated/
folder6/12.csv folder/anotherfolder/morefolder/evenmorefolder/generated/
I want to copy the csv file name from each line, paste them at the end of that line and append it with ".org". Hence, the changed file would look like
folder1/a_b.csv folder1/generated/a_b.csv.org
folder2/folder3/a_b1.csv folder12/generated/a_b1.csv.org
folder4/b_c.csv folder123/generated/b_c.csv.org
folder5/d.csv folder1/new_folder/generated/d.csv.org
folder6/12.csv folder/anotherfolder/morefolder/evenmorefolder/generated/12.csv.org
Basically, I am looking for a command in vim or sed using which I can search a pattern in each line and append it at the end of that line. Is it possible?
Thanks in advance.
Vim
Here's how to do this in Vim:
:%s/\([^/]*\.csv\)\( .*\)/&\1.org/
This global (:%) substitution matches the filename (characters that don't contain /, ending in .csv), and captures \(...\) it. It then matches the rest of the line, and captures that, too.
As a replacement, first keep the original match & (or \0), then append the first capture (\1) with the additional suffix.
sed
Though the regular expression syntax is somewhat different than in Vim, the identical expression can be used with sed:
sed -e 's/\([^/]*\.csv\)\( .*\)/&\1.org/' input
Alternatives
It looks like you want to do file renaming in batches. On Linux, the mmv command-line tool is well suited for that; you'll probably find many similar tools on the web, too.
This might work for you (GNU sed):
sed -r 's|/([^ ]*) .*|&\1.org|' file
I've researched other questions on here, but haven't really found one that works for me. I'm trying to select a specific line from a file and replace a string on that line with another string. So I have a file named my_course. I'm trying to modify a line in my_course that starts with "123". on that line I want to replace the string "0," with "1,". Help?
One possibility would be to use sed:
sed '/^123/ s/0/1/' my_course
In the first /../ part you just have to specify the pattern you are looking for ^123 for a line starting with 123.
In the s/from/to/ part you have specify the substitution to be performed.
Note that by default after substitution the file will be written to stdout. You might want to:
redirect the output using ... > my_new_course
perform the substitution "in place" using the -e switch to sed
If you are using the destructive in place variant you might want to use -iEXTENSION in addition to keep a copy with the given EXTENSION of the original version in case something goes wrong.
EDIT:
To match the desired lined with a prefix stored in a variable you have to enclose the sed script with double quotes " as using single qoutes ' will prevent variable expansion:
sed "/^$input/ s/0/1/" my_course
Have you tried this:
sed -e '[line]s/old_string/new_string/' my_course
PS: the [ ] shouldn't be used, is there just to make it clear that you should put the number right before the "s".
Cheers!
In fact, the -e in this case is not necessary, I can write just
sed '<line number>s/<old string>/<new string>/' my_course
This is what worked for me on Fedora 36, GNU bash, version 5.2.15(1)-release (x86_64-redhat-linux-gnu):
sed -i '1129s/additional/extra/' en-US/Design.xml
I know you said you couldn't use line numbers; I don't know how to address that part, but this replaced "additional" with "extra" on line 1129 of that file.
i have a template, with a var LINK
and a data file, links.txt, with one url per line
how in bash i can substitute LINK with the content of links.txt?
if i do
#!/bin/bash
LINKS=$(cat links.txt)
sed "s/LINKS/$LINK/g" template.xml
two problem:
$LINKS has the content of links.txt without newline
sed: 1: "s/LINKS/http://test ...": bad flag in substitute command: '/'
sed is not escaping the // in the links.txt file
thanks
Use some better language instead. I'd write a solution for bash + awk... but that's simply too much effort to go into. (See http://www.gnu.org/manual/gawk/gawk.html#Getline_002fVariable_002fFile if you really want to do that)
Just use any language where you don't have to mix control and content text. For example in python:
#!/usr/bin/env python
links = open('links.txt').read()
template = open('template.xml').read()
print template.replace('LINKS', links)
Watch out if you're trying to force sed solution with some other separator - you'll get into the same problems unless you find something disallowed in urls (but are you verifying that?) If you don't, you already have another problem - links can contain < and > and break your xml.
You can do this using ed:
ed template.xml <<EOF
/LINKS/d
.r links.txt
w output.txt
EOF
The first command will go to the line
containing LINKS and delete it.
The second line will insert the
contents of links.txt on the current
line.
The third command will write the file
to output.txt (if you omit output.txt
the edits will be saved to
template.xml).
Try running sed twice. On the first run, replace / with \/. The second run will be the same as what you currently have.
The character following the 's' in the sed command ends up the separator, so you'll want to use a character that is not present in the value of $LINK. For example, you could try a comma:
sed "s,LINKS,${LINK}\n,g" template.xml
Note that I also added a \n to add an additional newline.
Another option is to escape the forward slashes in $LINK, possibly using sed. If you don't have guarantees about the characters in $LINK, this may be safer.
I am writing a shell (bash) script and I'm trying to figure out an easy way to accomplish a simple task.
I have some string in a variable.
I don't know if this is relevant, but it can contain spaces, newlines, because actually this string is the content of a whole text file.
I want to replace the last occurence of a certain substring with something else.
Perhaps I could use a regexp for that, but there are two moments that confuse me:
I need to match from the end, not from the start
the substring that I want to scan for is fixed, not variable.
for truncating at the start: ${var#pattern}
truncating at the end ${var%pattern}
${var/pattern/repl} for general replacement
the patterns are 'filename' style expansion, and the last one can be prefixed with # or % to match only at the start or end (respectively)
it's all in the (long) bash manpage. check the "Parameter Expansion" chapter.
amn expression like this
s/match string here$/new string/
should do the trick - s is for sustitute, / break up the command, and the $ is the end of line marker. You can try this in vi to see if it does what you need.
I would look up the man pages for awk or sed.
Javier's answer is shell specific and won't work in all shells.
The sed answers that MrTelly and epochwolf alluded to are incomplete and should look something like this:
MyString="stuff ttto be edittted"
NewString=`echo $MyString | sed -e 's/\(.*\)ttt\(.*\)/\1xxx\2/'`
The reason this works without having to use the $ to mark the end is that the first '.*' is greedy and will attempt to gather up as much as possible while allowing the rest of the regular expression to be true.
This sed command should work fine in any shell context used.
Usually when I get stuck with Sed I use this page,
http://sed.sourceforge.net/sed1line.txt