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| Hi there My younger son who is now working in Germany just sent me your website and it was fascinating reading about your life since then eating missing everyone so much http://carringtonhf.servik.com/restaurant04e.html fresh car, http://basedlm.5nxs.com/restaurant973.html poultry, Great. | <<Anchor(faq19)>> == How can I split a file into line ranges, e.g. lines 1-10, 11-20, 21-30? == POSIX specifies the {{{split}}} utility, which can be used for this purpose: {{{#!highlight bash split -l 10 input.txt }}} For more flexibility you can use {{{sed}}}. The {{{sed}}} command can print e.g. the line number range 1-10: {{{#!highlight bash sed 10q # Print lines 1-10 and then quit. sed '1,5d; 10q' # Print just lines 6-10 by filtering the first 5 then quitting after 10. }}} The `d` command stops {{{sed}}} from printing each line. This could alternatively have been done by passing sed the `-n` option and printing lines with the `p` command rather than deleting them with `d`. It makes no difference. We can now use this to print an arbitrary range of a file (specified by line number): {{{#!highlight bash # POSIX shell file=/etc/passwd range=10 cur=1 last=$(awk 'END { print NR }' < "$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" "$file" > c"hunk.$(printf %04d "$chunk")" chunk=$((chunk + 1)) cur=$((cur + range)) done }}} The previous example uses POSIX [[ArithmeticExpression|arithmetic]], which older [[BourneShell|Bourne shells]] do not have. In that case the following example should be used instead: {{{#!highlight bash # legacy Bourne shell; assume no printf either file=/etc/passwd range=10 cur=1 last=`awk 'END { print NR }' < "$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" + "$range"` done }}} Awk can also be used to produce a more or less equivalent result: {{{#!highlight bash awk -v range=10 '{print > FILENAME "." (int((NR -1)/ range)+1)}' file }}} ---- CategoryShell |
How can I split a file into line ranges, e.g. lines 1-10, 11-20, 21-30?
POSIX specifies the split utility, which can be used for this purpose:
1 split -l 10 input.txt
For more flexibility you can use sed. The sed command can print e.g. the line number range 1-10:
The d command stops sed from printing each line. This could alternatively have been done by passing sed the -n option and printing lines with the p command rather than deleting them with d. It makes no difference.
We can now use this to print an arbitrary range of a file (specified by line number):
1 # POSIX shell
2 file=/etc/passwd
3 range=10
4 cur=1
5 last=$(awk 'END { print NR }' < "$file") # count number of lines
6 chunk=1
7 while [ "$cur" -lt "$last" ]
8 do
9 endofchunk=$((cur + range - 1))
10 sed -n -e "$cur,${endofchunk}p" -e "${endofchunk}q" "$file" > c"hunk.$(printf %04d "$chunk")"
11 chunk=$((chunk + 1))
12 cur=$((cur + range))
13 done
The previous example uses POSIX arithmetic, which older Bourne shells do not have. In that case the following example should be used instead:
1 # legacy Bourne shell; assume no printf either
2 file=/etc/passwd
3 range=10
4 cur=1
5 last=`awk 'END { print NR }' < "$file"` # count number of lines
6 chunk=1
7 while test "$cur" -lt "$last"
8 do
9 endofchunk=`expr $cur + $range - 1`
10 sed -n -e "$cur,${endofchunk}p" -e "${endofchunk}q" "$file" > "chunk.$chunk"
11 chunk=`expr "$chunk" + 1`
12 cur=`expr "$cur" + "$range"`
13 done
Awk can also be used to produce a more or less equivalent result:
1 awk -v range=10 '{print > FILENAME "." (int((NR -1)/ range)+1)}' file