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Comment: POSIX arithmetic instead of bash; also, both examples were WRONG. Rewrite.
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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): {{{ # POSIX shell file=/etc/passwd range=10 cur=1 last=$(wc -l < "$file") # count number of lines chunk=1 while [ $cur -lt $last ] do endofchunk=$(($cur + $range - 1)) sed -n -e "$cur,${endofchunk}p" -e "${endofchunk}q" "$file" > chunk.$(printf %04d $chunk) chunk=$(($chunk + 1)) cur=$(($cur + $range)) done }}} The previous example uses POSIX [:ArithmeticExpression:arithmetic], which older [:BourneShell:Bourne shells] do not have. In that case the following example should be used instead: {{{ # legacy Bourne shell; assume no printf either file=/etc/passwd range=10 cur=1 last=`wc -l < "$file"` # count number of lines chunk=1 while test $cur -lt $last do endofchunk=`expr $cur + $range - 1` sed -n -e "$cur,${endofchunk}p" -e "${endofchunk}q" "$file" > chunk.$chunk chunk=`expr $chunk + 1` cur=`expr $cur + $range` done }}} |
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Wery well! Steve and Jackie, Two people who have the strength, bravery and resolve to make me feel very proud and really rather humble to know them salad Very cool! http://dessertgd.interfree.it/recipeac0.html cocktail, Please More updates