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Breaking large file into small files

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# 1  
Old 03-05-2015
Breaking large file into small files
Dear all,
I have huge txt file with the input files for some setup_code. However for running my setup_code, I require txt files with maximum of 1000 input files
Please help me in suggesting way to break down this big txt file to small txt file of 1000 entries only.

thanks and Greetings,
Emily
# 2  
Old 03-05-2015
man split.
Did you consider the hints at the lower page border?
This User Gave Thanks to RudiC For This Post:
emily
# 3  
Old 03-05-2015
If each entry is a line and you want 10,000 lines try using the
head and tail commands to chop up the file in 10,000 line chunks.
You can probably put it in a for loop with the wc command to see
how many lines are in the file, hence the maximum number to extract.

Code:
head -10000 file_name.txt               > file1.txt
head -20000 file_name.txt | tail -10000 > file2.txt
head -30000 file_name.txt | tail -20000 > file2.txt
head -40000 file_name.txt | tail -30000 > file2.txt

This User Gave Thanks to gandolf989 For This Post:
emily
# 4  
Old 03-05-2015
Well, gandolf989, that appears to be a poor suggestion given that split will do this all in a single operation. You are wasting IO and CPU resources so it will be quite slow. Also, how would you know when to stop writing code or running your loop? There is no point reinventing a process that works very well already and lets you customise the beginning and end of the output files if you need to.


If the splitting up dependant on any condition other than record count, then csplit may be the tool for you, however without some sample data and rules to follow it's impossible to really know what you need.

Please wrap all code, file, input & output/errors in CODE tags as it makes them far easier to read and preserves multiple spaces and long lines in case these are important.


Thanks, in advance,
Robin
This User Gave Thanks to rbatte1 For This Post:
emily
# 5  
Old 03-05-2015
Hello emily/gandolf989,

If we need to split a file according to lines let's say 10'000 lines per file then following may help.
Code:
awk '{FILENAME="file"int((NR-1)/10000);print >> FILENAME}' Input_file

Thanks,
R. Singh
This User Gave Thanks to RavinderSingh13 For This Post:
emily
# 6  
Old 03-05-2015
Quote:
Originally Posted by RavinderSingh13
Hello emily/gandolf989,

If we need to split a file according to lines let's say 10'000 lines per file then following may help.
Code:
awk '{FILENAME="file"int((NR-1)/10000);print >> FILENAME}' Input_file

Thanks,
R. Singh
There seems to be a magic awk command for almost every problem.

---------- Post updated at 12:46 PM ---------- Previous update was at 12:44 PM ----------

Quote:
Originally Posted by rbatte1
Well, gandolf989, that appears to be a poor suggestion given that split will do this all in a single operation....
csplit might be a far better tool, I just haven't used it. There is certainly a size file where head/tail just won't work, but for many files it might work well enough.
This User Gave Thanks to gandolf989 For This Post:
emily
# 7  
Old 03-06-2015
thanks all for useful input, it work fine..Smilie

Greetings,

---------- Post updated at 03:13 AM ---------- Previous update was at 02:45 AM ----------

Hello,
I am not able to provide external parameter here..which is $3 while getting the desired output files..Smilie in this line
Code:
awk '{FILENAME="$3_"int((NR-1)/200)".txt";print >> FILENAME}' $3


Code:
#!/bin/bash                                                                                                                  
#usage ./copyTextFromCastor.sh $PATH $GREP $OUTPUTFILE                                                                       

PATHNAME=$1
CONSTANT=rfio:
GREP=$2
OUTPUT=$3

echo "Copying fileName \"$1 | grep $2\" to $3"
srmls "$PATHNAME" --count 99999 --offset 2 | grep "$2" | awk -F'tier2' '{print string path $2}' string="" path=""  > "$3"

echo "progressing ... please be patient..."

## split $3 into small size files, name InputFileN.txt                                                                       
awk '{FILENAME="$3_"int((NR-1)/200)".txt";print >> FILENAME}' $3
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