问题
I have a very long file which I want to print but skipping the first 1e6 lines for example. I look into the cat man page but I did not see any option to do this. I am looking for a command to do this or a simple bash program.
回答1:
You'll need tail. Some examples:
$ tail great-big-file.log
< Last 10 lines of great-big-file.log >
If you really need to SKIP a particular number of "first" lines, use
$ tail -n +<N+1> <filename>
< filename, excluding first N lines. >
That is, if you want to skip N lines, you start printing line N+1. Example:
$ tail -n +11 /tmp/myfile
< /tmp/myfile, starting at line 11, or skipping the first 10 lines. >
If you want to just see the last so many lines, omit the "+":
$ tail -n <N> <filename>
< last N lines of file. >
回答2:
Easiest way I found to remove the first ten lines of a file:
$ sed 1,10d file.txt
回答3:
If you have GNU tail available on your system, you can do the following:
tail -n +1000001 huge-file.log
It's the +
character that does what you want. To quote from the man page:
If the first character of K (the number of bytes or lines) is a `+', print beginning with the Kth item from the start of each file.
Thus, as noted in the comment, putting +1000001 starts printing with the first item after the first 1,000,000 lines.
回答4:
A less verbose version with AWK:
awk 'NR > 1e6' myfile.txt
But I would recommend using integer numbers.
回答5:
if you want to skip first two linetail -n +3 <filename>
if you want to skip first x line tail -n +$((x+1)) <filename>
回答6:
Use the sed delete command with a range address. For example:
$ sed 1,100d file.txt # Print file.txt omitting lines 1-100.
Alternatively, if you want to only print a known range use the print command with the -n
flag:
$ sed -n 201,300p file.txt # Print lines 201-300 from file.txt
This solution should work reliably on all UNIX systems, regardless of the presence of GNU utilities.
回答7:
Just to propose a sed
alternative. :) To skip first one million lines, try |sed '1,1000000d'
.
Example:
$ perl -wle 'print for (1..1_000_005)'|sed '1,1000000d'
1000001
1000002
1000003
1000004
1000005
回答8:
If you want to see first 10 line you can use sed as below:
sed -n '1,10 p' myFile.txt
or if you want to see lines from 20 to 30 you can use:
sed -n '20,30 p' myFile.txt
回答9:
This shell script works fine for me:
#!/bin/bash
awk -v initial_line=$1 -v end_line=$2 '{
if (NR >= initial_line && NR <= end_line)
print $0
}' $3
Used with this sample file (file.txt):
one
two
three
four
five
six
The command (it will extract from second to fourth line in the file):
edu@debian5:~$./script.sh 2 4 file.txt
Output of this command:
two
three
four
Of course, you can improve it, for example by testing that all argument values are the expected :-)
回答10:
sed -n '1d;p'
this command will delete the first line and print the rest
回答11:
You can do this using the head and tail commands:
head -n <num> | tail -n <lines to print>
where num is 1e6 + the number of lines you want to print.
回答12:
cat < File > | awk '{if(NR > 6) print $0}'
回答13:
I needed to do the same and found this thread.
I tried "tail -n +, but it just printed everything.
The more +lines worked nicely on the prompt, but it turned out it behaved totally different when run in headless mode (cronjob).
I finally wrote this myself:
skip=5
FILE="/tmp/filetoprint"
tail -n$((`cat "${FILE}" | wc -l` - skip)) "${FILE}"
来源:https://stackoverflow.com/questions/604864/print-a-file-skipping-first-x-lines-in-bash