awk ‘FNR==NR{a[$1]=$2 FS $3;next} here we handle the 1st input (file2). say, FS is space, we build an array(a) up, index is column1, value is column2 ” ” column3 the FNR==NR and next means, this part of codes work only for file2. you could man gawk check what are NR and FNR { print $0, … Read more
You can do this by swapping values of the first two fields: awk ‘ { t = $1; $1 = $2; $2 = t; print; } ‘ input_file
sed “s/^[ \t]*//” -i youfile Warning: this will overwrite the original file.
You can do it with cut: cut -d ” ” -f 3- input_filename > output_filename Explanation: cut: invoke the cut command -d ” “: use a single space as the delimiter (cut uses TAB by default) -f: specify fields to keep 3-: all the fields starting with field 3 input_filename: use this file as the … Read more
Never use the word “pattern” in this context as it is ambiguous. Always use “string” or “regexp” (or in shell “globbing pattern”), whichever it is you really mean. See How do I find the text that matches a pattern? for more about that. The specific answer you want is: awk ‘f{print;f=0} /regexp/{f=1}’ file or specializing … Read more
This appears to be what you want, based on the example you gave: sed -i ‘s/foo/bar/g’ * It is not recursive (it will not descend into subdirectories). For a nice solution replacing in selected files throughout a tree I would use find: find . -name ‘*.html’ -print -exec sed -i.bak ‘s/foo/bar/g’ {} \; The *.html … Read more
\d is a switch not a regular expression macro. If you want to use some predefined “constant” instead of [0-9] expression just try run this code: s/[[:digit:]]+//g
To append after the pattern: (-i is for in place replace). line1 and line2 are the lines you want to append(or prepend) sed -i ‘/pattern/a \ line1 \ line2’ inputfile Output: #cat inputfile pattern line1 line2 To prepend the lines before: sed -i ‘/pattern/i \ line1 \ line2’ inputfile Output: #cat inputfile line1 line2 pattern
Print lines between PAT1 and PAT2 $ awk ‘/PAT1/,/PAT2/’ file PAT1 3 – first block 4 PAT2 PAT1 7 – second block PAT2 PAT1 10 – third block Or, using variables: awk ‘/PAT1/{flag=1} flag; /PAT2/{flag=0}’ file How does this work? /PAT1/ matches lines having this text, as well as /PAT2/ does. /PAT1/{flag=1} sets the flag … Read more
Just use var = var1 var2 and it will automatically concatenate the vars var1 and var2: awk ‘{new_var=$1$2; print new_var}’ file You can put an space in between with: awk ‘{new_var=$1″ “$2; print new_var}’ file Which in fact is the same as using FS, because it defaults to the space: awk ‘{new_var=$1 FS $2; print … Read more