binary file file.f1
which has String abc I want to overwrite it with adcd
perl -pi -e s/abc/abcd/ file.f1
works but it inserts it rather than overwriting it, which causes error for the program which uses it
I'm not sure how will I be able to do that without making things more complex,
I'd prefer if it used tools like sed, grep, python, perl one liners which are available by default on UNIX system
I'm not very experienced user and am very new to these tools
edit- hope its clear now
data inside bin file is like
[abc def xyz]
when doing perl -pi -e s/abc/abcd/ file.f1
it becomes [abcd def xyz]
what i want is to overwrite it with a extra [space] so it becomes
[abcd ef xyz]
You are trying to patch a binary file. Perl RE are not set for this type of process. While they will work MOST time, specific sequences may trick the RE engine, which assume the file to be text. Use with care.
To get replacement, make the source string match the length of the target string
perl -pi -e 's/abc./abcd/' file.f1
Perl will replace the first 4 byte string that starts with abc with abcd. If you suspect that the 4th character may be special (e.g. new line, or similar), use the single line mode. It will allow '.' to match ANY character.
perl -pi -e 's/abc./abcd/s' file.f1
perl -pi -e 's/blue/red/g' $file_name
The g at the end is required. Another tool to use would be sed for these kinds of tasks.
Another post about using perl
Related
I want to clean my file before/after saving so I have to delete unnecessary characters that I have there. Sadly, even that my regex is working in Regex101, it does not work in shell script I wrote.
I am getting my list from Kubernetes via
kubectl get pods -n $1 -o jsonpath='{range .items[*]}{#.spec.containers[*].image}{","}{#.status.containerStatuses[*].imageID}{"\n"}{end}'
Then I saving it to the temp file and using sed to clear it - the regex should match and (sed should) delete any character between , and # (also should delete #). I am escaping them since they are special characters.
sed -i 's/(?<=\,)(.*?)(?<=\#)//g' temp
The problem is that this regex is working fine (for example in Regex101) but is not working with the sed command. I even tried awk but getting the same output.
awk '!/(?<=\,)(.*?)(?<=\#)/' temp
Am I missing something or is the regex acting differently somehow in Unix/shell?
Thanks for any input.
Example content of the file (for test):
docker.elastic.co/elasticsearch/elasticsearch:7.17.5,docker-pullable://docker.elastic.co/elasticsearch/elasticsearch#sha256:76344d5f89b13147743db0487eb76b03a7f9f0cd55abe8ab887069711f2ee27d
docker.io/bitnami/kafka:3.3.1-debian-11-r11,docker-pullable://bitnami/kafka#sha256:be29db0e37b6ab13df5fc14988a4aa64ee772c7f28b4b57898015cf7435ff662
docker.io/bitnami/mongodb:6.0.3-debian-11-r0,docker-pullable://bitnami/mongodb#sha256:e7438d7964481c0bcfcc8f31bca2d73022c0b7ba883143091a71ae01be6d9edb
docker.io/bitnami/postgresql:14.1.0-debian-10-r80,docker-pullable://bitnami/postgresql#sha256:6eb9c4ab3444e395df159e2cad21f283e4bf30802958467590c886f376dc9959
docker.io/bitnami/zookeeper:3.8.0-debian-11-r47,docker-pullable://bitnami/zookeeper#sha256:0f3169499c5ee02386c3cb262b2a0d3728998d9f0a94130a8161e389f61d1462
Expected output:
docker.elastic.co/elasticsearch/elasticsearch:7.17.5,sha256:76344d5f89b13147743db0487eb76b03a7f9f0cd55abe8ab887069711f2ee27d
docker.io/bitnami/kafka:3.3.1-debian-11-r11,sha256:be29db0e37b6ab13df5fc14988a4aa64ee772c7f28b4b57898015cf7435ff662
docker.io/bitnami/mongodb:6.0.3-debian-11-r0,sha256:e7438d7964481c0bcfcc8f31bca2d73022c0b7ba883143091a71ae01be6d9edb
docker.io/bitnami/postgresql:14.1.0-debian-10-r80,sha256:6eb9c4ab3444e395df159e2cad21f283e4bf30802958467590c886f376dc9959
docker.io/bitnami/zookeeper:3.8.0-debian-11-r47,sha256:0f3169499c5ee02386c3cb262b2a0d3728998d9f0a94130a8161e389f61d1462
You are trying to use Perl extensions which are not supported by more traditional regex tools like sed and Awk.
Perhaps see also Why are there so many different regular expression dialects? and the Stack Overflow regex tag info page.
If I can guess what you are trying to do, you want simply
sed -i 's/,[^#]*#/,/g' temp
The /g flag is unnecessary if you only expect one match per line.
Neither , nor # is a regex metacharacter; they do not require escaping.
Usually you would want to avoid using a temporary file or sed -i; perhaps simply
kubectl blah blah | sed 's/,[^#]*#/,/' > temp
to create the file, or remove the redirection if you want to pipe the results further.
I want to remove the first two characters of a column in a text file.
I am using the below but this is also truncating the headers.
sed -i 's/^..//' file1.txt
Below is my file:
FileName,Age
./Acct_Bal_Tgt.txt,7229
./IDQ_HB1.txt,5367
./IDQ_HB_LOGC.txt,5367
./IDQ_HB.txt,5367
./IGC_IDQ.txt,5448
./JobSchedule.txt,3851
I want the ./ to be removed from each line in the file name.
Transferring comments to an answer, as requested.
Modify your script to:
sed -e '2,$s/^..//' file1.txt
The 2,$ prefix limits the change to lines 2 to the end of the file, leaving line 1 unchanged.
An alternative is to remove . and / as the first two characters on a line:
sed -e 's%^[.]/%%' file1.txt
I tend to use -e to specify that the script option follows; it isn't necessary unless you split the script over several arguments (so it isn't necessary here where there's just one argument for the script). You could use \. instead of [.]; I'm allergic to backslashes (as you would be if you ever spent time working out whether you needed 8 or 16 consecutive backslashes to get the right result in a troff document).
Advice: Don't use the -i option until you've got your script working correctly. It overwrites your file with the incorrect output just as happily as it will with the correct output. Consequently, if you're asking about how to write a sed script on SO, it isn't safe to be using the -i option. Also note that the -i option is non-standard and behaves differently with different versions of sed (when it is supported at all). Specifically, on macOS, the BSD sed requires a suffix specified; if you don't want a backup, you have to use two arguments: -i ''.
Use this Perl one-liner:
perl -pe 's{^[.]/}{}' file1.txt > output.txt
The Perl one-liner uses these command line flags:
-e : Tells Perl to look for code in-line, instead of in a file.
-p : Loop over the input one line at a time, assigning it to $_ by default. Add print $_ after each loop iteration.
s{^[.]/}{} : Replace a literal dot ([.]) followed by a slash ('/'), found at the beginning of the line (^), with nothing (delete them). This does not modify the header since it does not match the regex.
If you prefer to modify the file in-place, you can use this:
perl -i.bak -pe 's{^[.]/}{}' file1.txt
This creates the backup file file1.txt.bak.
SEE ALSO:
perldoc perlrun: how to execute the Perl interpreter: command line switches
perldoc perlrequick: Perl regular expressions quick start
In the below text I would like to add figs/01/ to each of the 3 files. As you can see the files can either be pdf,png or not have an extension and sometimes the \includegraphics breaks over several lines.
My current thinking is
cat figs.tex | ruby -ne 'puts $_.gsub(/\\includegraphics\[.*?\]\{.*?\}/) { |x| x.do_something_here }'
but it is a chick and egg problem, because I would need to search again for the part to search and replace.
Question
Can anyone see how to solve such a situation?
\begin{figure}[ht]
\centerline{ \includegraphics[height=55mm]{plotLn} \includegraphics[height=55mm]{plotLnZoom.pdf}}
\caption{Funktionen $f(x) = \ln(x)$ \ref{examg0} (bl)}
\end{figure}
\begin{example}[Parameterfremstilling for ret linje]\label{tn6.linje}
\begin{think}
Givet linjen $\,m\,$,
\includegraphics[trim=1cm 11.5cm 1cm
11.5cm,width=0.60\textwidth,clip]{vektor8.png}
\end{think}
You can read the whole file in one shot (instead of the default behaviour that reads the file line by line). To do that you need the switch -0777 (special value for the record separator). This solves the problem of a pattern that spreads over multiple lines.
You can also replace the -n option and puts with -p to automatically print the result.
ruby -0777 -pe 'gsub(/\\includegraphics\[[^\]]*\]{\K/,"figs/01/")' figs.tex
You can omit $_, by default gsub is applied to it. (You can even impress your friends removing the space between -pe and the quote ')
About the pattern, \K removes all on the left from the match result, the match result here is only an empty string at the expected position where the replacement string is inserted.
Note that the ruby command line options come from Perl:
perl -0777 -pe 's!\\includegraphics\[[^\]]*\]{\K!figs/01/!g' figs.tex
I would like some advice on this script.
I'm trying to use sed (I didn't manage it with rename) to change a file that contains lines of the format (my test file name is sedtest):
COPY W:\Interfaces\Payments\Tameia\Unprocessed\X151008\E*.*
(that's not the only content of the file).
My goal is to replace the 151008 date part with a different date, I've tried to come up with a solution in sed using this:
sed -i -e "s/Unprocessed\X.*/Unprocessed\X'BLABLA'/" sedtest
but it doesnt seem to work, the line remains unchanged, it's like it doesn't recognize the pattern because of the \. I've tried some alternative delimiters like #, but to no avail.
Thanks in advance for any advice.
There's a couple of issues with your sed command. I would suggest changing it to this:
sed -r 's/(Unprocessed\\X)[0-9]+/\1BLABLA/' file
Since your version of sed supports -i without requiring that you add a suffix to create a backup file, I assume you're using the GNU version, which also supports extended regular expressions with the -r switch. The command captures the part within the () and uses it in the replacement \1. Don't forget that backslashes must be escaped.
If you're going to use -i, I would recommend doing so like -i.bak, so a backup of your file is made to file.bak before it is overwritten.
You haven't shown the exact output you were looking for but I assumed that you wanted the line to become:
COPY W:\Interfaces\Payments\Tameia\Unprocessed\XBLABLA\E*.*
Remember that * is greedy, so .* would match everything up to the end of the line. That's why I changed it to [0-9]+, so that only the digits were replaced, leaving the rest of the line intact.
As you've mentioned using a variable in the replacement, you should use something like this:
sed -r -i.bak "s/(Unprocessed\\X)[0-9]+/\1$var/" file
This assumes that $var is safe to use, i.e. doesn't contain characters that will be interpreted by sed, like \, / or &. See this question for details on handling such cases reliably.
For some reason I can't seem to find a straightforward answer to this and I'm on a bit of a time crunch at the moment. How would I go about inserting a choice line of text after the first line matching a specific string using the sed command. I have ...
CLIENTSCRIPT="foo"
CLIENTFILE="bar"
And I want insert a line after the CLIENTSCRIPT= line resulting in ...
CLIENTSCRIPT="foo"
CLIENTSCRIPT2="hello"
CLIENTFILE="bar"
Try doing this using GNU sed:
sed '/CLIENTSCRIPT="foo"/a CLIENTSCRIPT2="hello"' file
if you want to substitute in-place, use
sed -i '/CLIENTSCRIPT="foo"/a CLIENTSCRIPT2="hello"' file
Output
CLIENTSCRIPT="foo"
CLIENTSCRIPT2="hello"
CLIENTFILE="bar"
Doc
see sed doc and search \a (append)
Note the standard sed syntax (as in POSIX, so supported by all conforming sed implementations around (GNU, OS/X, BSD, Solaris...)):
sed '/CLIENTSCRIPT=/a\
CLIENTSCRIPT2="hello"' file
Or on one line:
sed -e '/CLIENTSCRIPT=/a\' -e 'CLIENTSCRIPT2="hello"' file
(-expressions (and the contents of -files) are joined with newlines to make up the sed script sed interprets).
The -i option for in-place editing is also a GNU extension, some other implementations (like FreeBSD's) support -i '' for that.
Alternatively, for portability, you can use perl instead:
perl -pi -e '$_ .= qq(CLIENTSCRIPT2="hello"\n) if /CLIENTSCRIPT=/' file
Or you could use ed or ex:
printf '%s\n' /CLIENTSCRIPT=/a 'CLIENTSCRIPT2="hello"' . w q | ex -s file
Sed command that works on MacOS (at least, OS 10) and Unix alike (ie. doesn't require gnu sed like Gilles' (currently accepted) one does):
sed -e '/CLIENTSCRIPT="foo"/a\'$'\n''CLIENTSCRIPT2="hello"' file
This works in bash and maybe other shells too that know the $'\n' evaluation quote style. Everything can be on one line and work in
older/POSIX sed commands. If there might be multiple lines matching the CLIENTSCRIPT="foo" (or your equivalent) and you wish to only add the extra line the first time, you can rework it as follows:
sed -e '/^ *CLIENTSCRIPT="foo"/b ins' -e b -e ':ins' -e 'a\'$'\n''CLIENTSCRIPT2="hello"' -e ': done' -e 'n;b done' file
(this creates a loop after the line insertion code that just cycles through the rest of the file, never getting back to the first sed command again).
You might notice I added a '^ *' to the matching pattern in case that line shows up in a comment, say, or is indented. Its not 100% perfect but covers some other situations likely to be common. Adjust as required...
These two solutions also get round the problem (for the generic solution to adding a line) that if your new inserted line contains unescaped backslashes or ampersands they will be interpreted by sed and likely not come out the same, just like the \n is - eg. \0 would be the first line matched. Especially handy if you're adding a line that comes from a variable where you'd otherwise have to escape everything first using ${var//} before, or another sed statement etc.
This solution is a little less messy in scripts (that quoting and \n is not easy to read though), when you don't want to put the replacement text for the a command at the start of a line if say, in a function with indented lines. I've taken advantage that $'\n' is evaluated to a newline by the shell, its not in regular '\n' single-quoted values.
Its getting long enough though that I think perl/even awk might win due to being more readable.
A POSIX compliant one using the s command:
sed '/CLIENTSCRIPT="foo"/s/.*/&\
CLIENTSCRIPT2="hello"/' file
Maybe a bit late to post an answer for this, but I found some of the above solutions a bit cumbersome.
I tried simple string replacement in sed and it worked:
sed 's/CLIENTSCRIPT="foo"/&\nCLIENTSCRIPT2="hello"/' file
& sign reflects the matched string, and then you add \n and the new line.
As mentioned, if you want to do it in-place:
sed -i 's/CLIENTSCRIPT="foo"/&\nCLIENTSCRIPT2="hello"/' file
Another thing. You can match using an expression:
sed -i 's/CLIENTSCRIPT=.*/&\nCLIENTSCRIPT2="hello"/' file
Hope this helps someone
The awk variant :
awk '1;/CLIENTSCRIPT=/{print "CLIENTSCRIPT2=\"hello\""}' file
I had a similar task, and was not able to get the above perl solution to work.
Here is my solution:
perl -i -pe "BEGIN{undef $/;} s/^\[mysqld\]$/[mysqld]\n\ncollation-server = utf8_unicode_ci\n/sgm" /etc/mysql/my.cnf
Explanation:
Uses a regular expression to search for a line in my /etc/mysql/my.cnf file that contained only [mysqld] and replaced it with
[mysqld]
collation-server = utf8_unicode_ci
effectively adding the collation-server = utf8_unicode_ci line after the line containing [mysqld].
I had to do this recently as well for both Mac and Linux OS's and after browsing through many posts and trying many things out, in my particular opinion I never got to where I wanted to which is: a simple enough to understand solution using well known and standard commands with simple patterns, one liner, portable, expandable to add in more constraints. Then I tried to looked at it with a different perspective, that's when I realized i could do without the "one liner" option if a "2-liner" met the rest of my criteria. At the end I came up with this solution I like that works in both Ubuntu and Mac which i wanted to share with everyone:
insertLine=$(( $(grep -n "foo" sample.txt | cut -f1 -d: | head -1) + 1 ))
sed -i -e "$insertLine"' i\'$'\n''bar'$'\n' sample.txt
In first command, grep looks for line numbers containing "foo", cut/head selects 1st occurrence, and the arithmetic op increments that first occurrence line number by 1 since I want to insert after the occurrence.
In second command, it's an in-place file edit, "i" for inserting: an ansi-c quoting new line, "bar", then another new line. The result is adding a new line containing "bar" after the "foo" line. Each of these 2 commands can be expanded to more complex operations and matching.