I have a text file of 5000000 lines and I want to extract one line from each 1000 and write them into a new text file. The new text file should be of 5000 line.
Can you help me?
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2Which shell? What have you tried? – Politank-Z Jun 02 '15 at 15:41
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Which line, the first one or the last one? – kenorb Jun 02 '15 at 15:54
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Please show your work. – muglio Jun 02 '15 at 15:59
3 Answers
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I would use a python script to do so. However, the same logic can be used with your shell as well. Here is the python code.
input_file = 'path/file.txt'
output_file = 'path/output.txt'
n = 0
with open(input_file, 'r') as f:
with ope(output_file, 'w') as o:
for line in f:
n += 1
if n == 1000:
o.write(line)
n = 0
Basically, you initialise a counter then you iterate over the file line by line, you increment the counter for each line, if the counter hits 1000 you write the line in the new file and reset the counter back.
Here is how to iterate over lines of a file using Bash shell.
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alec_djinn
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Try:
awk 'NR%1000==1' infile > outfile
see this link for more options: remove odd or even lines from text file in terminal in linux
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pasaba por aqui
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You can use either head or tail, depends which line you'd like to extract.
To extract first line from each file (for instance *.txt files):
head -n1 *.txt | grep -ve ^= -e ^$ > first.txt
To extract the last line from each file, simply use tail instead of head.
For extracting specific line, see: How do I use Head and Tail to print specific lines of a file.
