Programming :: Sed One-liner: Search Text In File And Replace It - If Not Present Insert It?
Oct 16, 2010
As indicated in the subject, I want to search a text. If the text is present I want to replace it. But if the text is not present, I want to insert it after first line and before last line.
Something very handy to do in a Linux shell, is manipulating files and strings - essentially parsing data. Write a utility which will scan in a text file and search and replace strings. We also want to keep track of how many strings we've replaced.
I know that my command would look like this: <utility name> <filename> <stringToSearchFor> <stringToReplaceWith> Code: #!/bin/bash
On windows I really only used Notepad++ as my text editor, it had two features that I loved.What I need to accomplish is what I would do with Notepad++ column editor.I could have like 100 lines, and place the cursor at a column, and goto edit>column editor, and I could insert an incrementing number. (I could also pad the incrementing number with 0s, this was GREAT for making batch files among other things.)So each line at that column had a number higher than the previous line.The other feature that I used sometimes was a search/replace with regex patterns.Does anyone know of an editor that has those features for linux? I am mostly after the column editor insert feature but if you know of one with both features that would rock.
I want to search a file for a particular pattern and if pattern found replace the line with new text. i am using awk 'match($0,"pattern") != 0 {print $0} ' filename to check if the pattern exists.how do i get the line number of the pattern and delete that line and replace the line with my new text?
I want to read from the file and check for the pattern, if the line has some word like <string>: then string should be copied into buffer. Afterwards, I want to insert the same <string> with some word in the next line of the file. use sed command to perform the above mentioned operations?
i need to change a binary file, let's say to find and replace username:
find string: "/home/name/bla-bla-bla/ " new string: "/home/anewname/bla-bla-bla/ "
i can do it, for example, in emacs (hexl-mode), but interesting in writing a script instead. it will be much more better for me if i could do it automatically. is there an analog of: sed 's/string1/string2/g' ? P.S. the best way is to recompile the binary files i have, but there are no sources available.
I'm wanting to mod some PHP files across a hierarchy and thought I'd drive it with find + grep + xargs
I built up a command line which I was confident would do the job, but now can't save the results.
First I tried this:
Code: find . -name *.php | xargs grep serialize | cut -d: -f1| sort -u | xargs sed -i s/serialize/serialise/g but that didn't work: Code: sed: illegal option -- i so I thought I'd try using Code:
Im trying to read a file in c++ and search for particular character for example if this is a list that I have:
Alice Bob David
[code]....
if the input is D, it should give David, if its B, gives bob. so in this case, meaning it reads the first character of every line. but if possible I want to make this dynamic so the user can specify which character position he is looking for, so in case he is looking for R as character index 3 in all lines, it should give Charlie. but the problem is, it does now recognize , besides, I do not know how to specify the character position in each line.
im tryin to make a tool in visual C++ which will take an input string through a text box,then it will compare tht string with a text file containing data and display the matched results in list box.
This is what I have right now. Well, I thought I knew sed, and apparently I don't... I tried writing this for someone else, and this has given me trouble, so since the user pretty much figured it out on his own, here it goes. Say VARR=1, so VARX and VARY contain the above text, appended by 1. What I am trying to do is replace the text "defaults.ctl.card 0" by VARX and "defaults.pcm.card 0" by VARY. The contents of FILE1 is the file being used to search for both text fields, and FILE2 is the output file. I tried using single quotes, double quotes, and a mixture of both, and no go whatsoever. So my question... What is the proper way of searching for text within a file and replacing with a variable?
Is there any way to use sed to replace certain text in a file with the persons username automatically? Right now i'm using Code: Select allsed -i.bak s/STRING_TO_REPLACE/STRING_TO_REPLACE_IT/g file.foo
I would like it to automatically inject the persons usrname in the replacement string. Is this possible? I've been looking on line at various sed tutorials and I cant quite find what i'm looking for. I also didn't really see anything in the forums search function.Essentially i'm trying to take this file URL...Android.rules and replace all instances of username with the persons actual username automatically.
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'm trying to use sed to search and replace backwards. The problem is that I have a shell script that is required to put commas into big numbers. For example
9999999 as 9,999,999
I've tried a few things, but none seem to work:
Code:
$ echo 9999999 | sed -e 's/([0-9]{3})/,1/g' ,999,9999 $ echo 9999999 | sed -e 's/([0-9]{3})$/1,/g' -e 's/([0-9]{3})/1,/g' 999,999,9, $ echo 9999999 | sed -e 's/([0-9]{3})$/1,/g' -e 's/([0-9]{3})/,1/g'
[ode]....
It would be much easier if I could search backwards! For example Bash parameter substitution style:
i trying to add text messge in textarea and i got error in connection and i don't know if it correct syntax. and i wonder when i was install xamp server it no password required. but i dont know what password that i input in my php connection.?
I need a command to search a string in a file and then to convert the next string in the same line from hexadecimal to binary. I was able to put everything in capitals. The original file can be as such:
E 2 C 1 794 T ffff E 2 C 1 787
It is not always FFFF! I am trying to do this in a file at once, not reading line by line (using while).
I would like to insert prior to the word "three" all items from this second file with the following contents:
Code:
four three two one
Now my issue is, and I have been using both sed and awk currently, that after the second line of the new file is read there will of course now be 2 copies of the word "three" but I would like to only insert the final 2 words, ie "two" and "one" prior to only the first occurrence of the word "three" so final file will look like:
Code:
one two four
[code]....
So here there is now only one of each word from the second file joined to make the new file. For simple code I have tried something like the following:
Code:
while read line do awk -v n=$line '!f && /three/{print n;f++}1' file1 > tmp_file mv tmp_file file1 done < file2
Now this works but seems very clumsy to me. There is obviously a better sed and / or awk out there.
(if need be, i think i can just add another line of "-e /s/char/newchar/" if i need to target more charecters or words as needed.) the issue with the above code. . . how do i get it to target whatever text file follows the command? without having to manually designate sed to it each time? e.g. in commanding:
When I grep kernel.exec-shield I get both line, hence I keep over writing the kernel.exec-shield-randomize in my script because it finds them both for my sed commend.
How can I get an exact match with either sed/awk/grep in shell so I can do a find and replace?
Example: sed 's/^kernel.exec-shield =.*/kernel.exec-shield = 1/g' /etc/sysctl.conf will replace BOTH lines
Example: grep "^kernel.exec-shield" find both line and I want it to find only the exact line.
I recently noticed some of my one-liners with && and || didn't work as I expected so I googled for "bash && || pitfalls" and found this page [URL] It's probably my fault, but I still don't understand why it wouldn't work as I want it..... I don't even have the code anymore that wasn't working properly because I rewrote it using if ; then ; command ; fi
i was wondering if in all the editors/tools in linux, if there was a prog that can extract a portion of a text file, giving it a starting line of say o as the first character on a line of say o35565 oxxxxx then when it finds the next line down the file with the same thing oxxxxwhatever
it could take those lines and all the lines between them and save it to another file? i dont know if you call this parsing? or what.
I am trying to construct a quick regex that will search for six lines of text without a clear line break between them. It only needs to search, not replace, as I will be using in gEdit (with regex plugin) anyway.
It's for editing subtitle files. The video player I will be using them on can only cope with 3-line subtitles, so I just need to edit any in the srt file that contain four or more. There won't be many so I can do it manually. For example:
26 00:01:47,357 --> 00:01:49,359 a motivated business professional with clearly defined goals.
[Code].....
but .* seems to mean "any character, or none", so that doesn't work. My experience of regular expressions is limited, but I do know they are very powerful when used correctly!
