Programming :: Replace 2nd Occurrence Of A String In A File - Sed Or Awk?
Apr 5, 2010
I know how to replace a particular instance (say 3rd one) of a word in a line using sed based on the sed one-liners. However I would like to replace a particular instance of a word in the entire file.
For example, here is a file:
Code:
John
Betty
Jack
Ron
Jack
Paul
So now I would like to replace the second instance of Jack (in red color) with "Rob" (for example). Not quite sure how to do that? I tried couple of things from here but they did not work.
I have script that I'm working on that updates a username in all the files that are called blah.inc for my framework. since i host a bunch of these web apps i need to do it to all of them. so I need to figure out how to update these files automagically with out me watching it to call vim every time. heres what I have so far
Code:
This finds the files but now i need to figure out how to do s/bob/fred/g on those files.
I want to use SED to do the following: In a text file replace any occurrences of the three character string ZZZ with a quotation mark "and. replace all occurrences of a comma with a semi-colon. It is the S/ / / command which is stumping me on the first issue...inparticular how to get the replace string to be quote.
I wanted to find and replace a string from a perl file. I have written a script in bash which runs the following command.
perl -pi -e "s/$findstring/$replacestring/" testfile where as $findstring = print F_WC_TMP"$line "; and $replaceString = $line = join ' ', split ' ', $line; print F_WC_TMP"$line ";
But when I am running the above command, i think it is replacing the $findstring with the above mentioned string and hence it contains a $line, it is looking for the variable $line and not finding the exact string. I am confused about how to search for a string that contains $ in it and replace it with another $string.
I have a line in a text file that has 40 random characters within a tag and i want to change the characters to a new set of 40 random characters (alphanumeric a-z 0-9 etc)
The line in the text file looks like this:
Quote:
How would i go about doing that?
Also second question same as the above but how would i remove them instead of replacing them?
If I have a word in a text file and I need to replace it by another word (for example, i need to replace abc by fff) so what is the command I can type it?
I am trying to replacee all digits with a symbol (say, big U here) in a string by
[code]...
The result become 'UsUoUmUeUtUhUiUnUgU' instead of 'somethingUUU' as expected. Looks like my string contains some 'hidden digits' in between the letters. Does anyone have an idea about that?
I am having difficulty getting sed to replace a string of text in an XML file, despite the fact that I have no trouble using grep to find that same string. Since the new string and old string to be replaced contain a lot of special characters, I thought it best to store them in variables as opposed to using a slew of backslashes:
I have large text files with space delimited strings (2-5). The strings can contain "'" or "-". I'd like to replace say the second space with a pipe. What's the best way to go? Using sed I was thinking of this:
I need to replace a string in a file(startup.sh) using a script(parser.sh). After running parser.sh startup.sh should be filled with nfs path like /home/vimal etc but im getting error since path contains /. how to remove this.
I want to replace a string of directory path in a string to empty:
Code:
But this doesnt seem to give me the desired thing:
Code:
This gives the desired outcome, but its specific, i need a variable in the sed not a string. And if I replace STRING="/mnt/sda1/record/$dd/" then I cant use it for something else, cause its has all the weird backslashes now.
i use this script to get the time and date of back and fourth transactions for a particular execution id. I use a substr command on the 5th column to to cut the milli seconds off the time value. - otherwise the times would look like 08:30:04.235
Moving right along, I have a folder of MP3 files containing various Movie sound tracks and scores. I'm using Audio Tag Tool to tag all the files at once with an "Artist" of "Soundtrack", and to inherit the "Title" tag from the file name. After that, I will rename all the files (Using Audio Tag Tool -- awesome program, btw) with the format "<Artist> - <Title>.mp3"
The problem, is many of my files already contain the string "Soundtrack", which would be redundant. I happen to be a perfectionist, so I'm unable to ignore it and move on. Hence my question to you fine folk: I want to delete all instances of "soundtrack" (-i case irrelevant) in the filenames before I go through the above steps. But, its not quite that simple. This is a sample of some of the file names:
Any solution using awk/sed/regexp or other standard linux utility (this is for a mix of RH versions)? I am dealing with some very large application log files. I want to see everything that has been written to the log since the last application restart.
For an example take a log file like this: Code: # cat test.log 1 msg 2 msg 3 restart 1 4 msg 5 restart 2 6 msg
The following command is close to what I want: Code: # awk '/restart/,G' test.log 3 restart 1 4 msg 5 restart 2 6 msg
But the awk command grabs the first restart not the last. If it was working the way I wanted I would see something like this: Code: # awk '/restart/,G' test.log 5 restart 2 6 msg
So, I need something in that search pattern that says look for the last occurrence. I know how to do this with a pipe line - I could reverse the file and then do a similar awk and reverse back, or I could find the number associated with the last restart and then use that in the awk search. But these just take too long because the file is too big.
There are a few things I was wondering about (using tools available in bash):How to insert a file at at the specified location of another.How to copy a portion of a file between two lines matching a regex to another file (and/or making sed only work between two lines matching a regex)How would you do this?
I have a file in which I have string called "already there" in some line of it. I want that if the string is present enter some loop..
like if(( grep "already there" $file is true )) then -- -- fi
But the thing is when I make grep it gives the whole line in which this string is present and gives some error: if[ grep "already there" file ]: command not found. I am very new to shell scripting.
