All of the lines with comments in a file begin with #. How can I delete all of the lines (and only those lines) which begin with #? Other lines containing #, but not at the beginning of the line should be ignored. 8 Answers 8
Is there any bash command that will let you get the nth line of STDOUT? That is to say, something that would take this $ ls -l -rw-r–r–@ 1 root wheel my.txt -rw-r–r–@ 1 root wheel files.txt -rw-r–r–@ 1 root wheel here.txt and do something like $ ls -l | magic-command 2 -rw-r–r–@ 1 root … Read more
The following command is correctly changing the contents of 2 files. sed -i ‘s/abc/xyz/g’ xaa1 xab1 But what I need to do is to change several such files dynamically and I do not know the file names. I want to write a command that will read all the files from current directory starting with xa* … Read more
grep -A1 ‘blah’ logfile Thanks to this command for every line that has ‘blah’ in it, I get the output of the line that contains ‘blah’ and the next line that follows in the logfile. It might be a simple one but I can’t find a way to omit the line that has ‘blah’ and … Read more
I need to retrieve last 100 lines of logs from the log file. I tried the sed command sed -n -e ‘100,$p’ logfilename Please let me know how can I change this command to specifically retrieve the last 100 lines. 6 Answers 6
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So far I’ve been able to find out how to add a line at the beginning of a file but that’s not exactly what I want. I’ll show it with an example: File content some text at the beginning Result <added text> some text at the beginning It’s similar but I don’t want to create … Read more
I would like to update a large number of C++ source files with an extra include directive before any existing #includes. For this sort of task, I normally use a small bash script with sed to re-write the file. How do I get sed to replace just the first occurrence of a string in a … Read more
If I run these commands from a script: #my.sh PWD=bla sed ‘s/xxx/’$PWD”https://stackoverflow.com/” … $ ./my.sh xxx bla it is fine. But, if I run: #my.sh sed ‘s/xxx/’$PWD”https://stackoverflow.com/” … $ ./my.sh $ sed: -e expression #1, char 8: Unknown option to `s’ I read in tutorials that to substitute environment variables from shell you need to … Read more
Being forced to use CVS for a current client and the address changed for the remote repo. The only way I can find to change the remote address in my local code is a recursive search and replace. However, with the sed command I’d expect to work: find ./ -type f -exec sed -i “s/192.168.20.1/new.domain.com/” … Read more
