For anyone who found this question due to a similar error message, but caused by an attempt to in-place edit on Mac OS X As per https://github.com/lmquang/til/issues/18: OS X requires the extension to be explicitly specified. The workaround is to set an empty string: $ sed -i ” ‘s/megatron/pony/g’ /path/to/file.txt ^^ man sed: -i extension … Read more
In general, do use this syntax: sed “s/<expression>/$(command)/” file This will look for <expression> and replace it with the output of command. For your specific problem, you can use the following: sed “s/0/$(date +%s)/g” input.txt > output.txt This replaces any 0 present in the file with the output of the command date +%s. Note you … Read more
I’m not sure if I got your question right, so here are some shots in the dark: Print last occurence of x (regex): grep x file | tail -1 Alternatively: tac file | grep -m1 x Print file from first matching line to end: awk ‘/x/{flag = 1}; flag’ file Print file from last matching … Read more
The delimiters // that you’re using are not for the d command, they’re for the addressing. I think you’re comparing them to the slashes in the s/// command… However although both relate to regular expressions, they are different contexts. The address (which appears before the command) filters which lines the command is applied to… The … Read more
A bit late to the party but for the benefit of others, I found the ‘w’ flag to be exactly what I was looking for. sed -i “s/$pattern/$new_pattern/w changelog.txt” “$filename” if [ -s changelog.txt ]; then # CHANGES MADE, DO SOME STUFF HERE else # NO CHANGES MADE, DO SOME OTHER STUFF HERE fi changelog.txt … Read more
You can use the r command. When you find a ‘fox’ in the input… /fox/{ …replace it for nothing… s/fox//g …and read the input file: r f.html } If you have a file such as: $ cat file.txt the quick brown fox jumps over the lazy dog fox dog the result is: $ sed ‘/fox/{ … Read more
Use $ a. sed -i “$ a some text” somefile.txt
You could do this purely in bash using the double square bracket [[ ]] test operator, which stores results in an array called BASH_REMATCH: [[ “TestT100String” =~ ([0-9]+) ]] && echo “${BASH_REMATCH[1]}”
Use this sed command: sed -i.old ‘/^[#*-]\{0,1\}blubb/d’ special.conf OR sed -i.old -E ‘/^[#*-]?blubb/d’ special.conf OR sed -i.old -r ‘/^[#*-]?blubb/d’ special.conf
Capture the whole line that contains myvar: $ sed ‘s/\(^.*myvar.*$\)/\/\/\1/’ file $ cat hw.java class hw { public static void main(String[] args) { System.out.println(“Hello World!”); myvar=1 } } $ sed ‘s/\(^.*myvar.*$\)/\/\/\1/’ hw.java class hw { public static void main(String[] args) { System.out.println(“Hello World!”); // myvar=1 } } Use the -i option to save the changes … Read more