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| [[Anchor(faq19)]] == How can I split a file into line ranges, e.g. lines 1-10, 11-20, 21-30? == Some Unix systems provide the {{{split}}} utility for this purpose: {{{ split --lines 10 --numeric-suffixes input.txt output- }}} For more flexibility you can use {{{sed}}}. The {{{sed}}} command can print e.g. the line number range 1-10: {{{ sed -n '1,10p' }}} This stops {{{sed}}} from printing each line ({{{-n}}}). Instead it only processes the lines in the range 1-10 ("1,10"), and prints them ("p"). {{{sed}}} still reads the input until the end, although we are only interested in lines 1 though 10. We can speed this up by making {{{sed}}} terminate immediately after printing line 10: {{{ sed -n -e '1,10p' -e '10q' }}} Now the command will quit after reading line 10 ("10q"). The {{{-e}}} arguments indicate a script (instead of a file name). The same can be written a little shorter: {{{ sed -n '1,10p;10q' }}} We can now use this to print an arbitrary range of a file (specified by line number): {{{ file=/etc/passwd range=10 firstline=1 maxlines=$(wc -l < "$file") # count number of lines while (($firstline < $maxlines)) do ((lastline=$firstline+$range+1)) sed -n -e "$firstline,${lastline}p" -e "${lastline}q" "$file" ((firstline=$firstline+$range+1)) done }}} This example uses ["BASH"] and KornShell ArithmeticExpressions, which older [wiki:Self:BourneShell Bourne shells] do not have. In that case the following example should be used instead: {{{ file=/etc/passwd range=10 firstline=1 maxlines=`wc -l < "$file"` # count line numbers while [ $firstline -le $maxlines ] do lastline=`expr $firstline + $range + 1` sed -n -e "$firstline,${lastline}p" -e "${lastline}q" "$file" firstline=`expr $lastline + 1` done }}} |
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Good morning to all of you... A watershed moment, ok stuff happens, but if that guy can deal with marshalling after it damn near killed him, what have I got to worry about? My team that weekend played a blinder & we got the job done, the reports filed, the drivers reported for bad driving, the whole nine yards def jam icon no optical audio I've just been sitting around waiting for something to happen. http://deck69.ifrance.com/recipee3b.html watermellon cake thick, http://necklace56.ifrance.com/recipe4b3.html recipe ideas for hot dogs, Best Wishes!!