I was wondering if it was possible to split a file into equal parts (edit: = all equal except for the last), without breaking the line? Using the split command in Unix, lines may be broken in half. Is there a way to, say, split up a file in 5 equal parts, but have it still only consist of whole lines (it's no problem if one of the files is a little larger or smaller)? I know I could just calculate the number of lines, but I have to do this for a lot of files in a bash script. Many thanks!
I made a bash script, that given a number of parts as input, split a file
#!/bin/sh
parts_total="$2";
input="$1";
parts=$((parts_total))
for i in $(seq 0 $((parts_total-2))); do
lines=$(wc -l "$input" | cut -f 1 -d" ")
#n is rounded, 1.3 to 2, 1.6 to 2, 1 to 1
n=$(awk -v lines=$lines -v parts=$parts 'BEGIN {
n = lines/parts;
rounded = sprintf("%.0f", n);
if(n>rounded){
print rounded + 1;
}else{
print rounded;
}
}');
head -$n "$input" > split${i}
tail -$((lines-n)) "$input" > .tmp${i}
input=".tmp${i}"
parts=$((parts-1));
done
mv .tmp$((parts_total-2)) split$((parts_total-1))
rm .tmp*
I used head and tail commands, and store in tmp files, for split the files
#10 means 10 parts
sh mysplitXparts.sh input_file 10
or with awk, where 0.1 is 10% => 10 parts, or 0.334 is 3 parts
awk -v size=$(wc -l < input) -v perc=0.1 '{
nfile = int(NR/(size*perc));
if(nfile >= 1/perc){
nfile--;
}
print > "split_"nfile
}' input
A simple solution for a simple question:
split -n l/5 your_file.txt
no need for scripting here.
From the man file, CHUNKS may be:
l/N split into N files without splitting lines
Update
Not all unix dist include this flag. For example, it will not work in OSX. To use it, you can consider replacing the Mac OS X utilities with GNU core utilities.
var dict = File.ReadLines("test.txt")
.Where(line => !string.IsNullOrWhitespace(line))
.Select(line => line.Split(new char[] { '=' }, 2, 0))
.ToDictionary(parts => parts[0], parts => parts[1]);
or
enter code here
line="[email protected][email protected]";
string[] tokens = line.Split(new char[] { '=' }, 2, 0);
ans:
tokens[0]=to
token[1][email protected][email protected]"
The script isn't even necessary, split(1) supports the wanted feature out of the box:
split -l 75 auth.log auth.log.
The above command splits the file in chunks of 75 lines a piece, and outputs file on the form: auth.log.aa, auth.log.ab, ...
wc -l on the original file and output gives:
321 auth.log
75 auth.log.aa
75 auth.log.ab
75 auth.log.ac
75 auth.log.ad
21 auth.log.ae
642 total
split was updated in coreutils release 8.8 (announced 22 Dec 2010) with the --number option to generate a specific number of files. The option --number=l/n generates n files without splitting lines.
http://www.gnu.org/software/coreutils/manual/html_node/split-invocation.html#split-invocation http://savannah.gnu.org/forum/forum.php?forum_id=6662
Source: Stackoverflow.com