Try tail:
tail -n +2 "$FILE"
-n x: Just print the last x lines. tail -n 5 would give you the last 5 lines of the input. The + sign kind of inverts the argument and make tail print anything but the first x-1 lines. tail -n +1 would print the whole file, tail -n +2 everything but the first line, etc.
GNU tail is much faster than sed. tail is also available on BSD and the -n +2 flag is consistent across both tools. Check the FreeBSD or OS X man pages for more.
The BSD version can be much slower than sed, though. I wonder how they managed that; tail should just read a file line by line while sed does pretty complex operations involving interpreting a script, applying regular expressions and the like.
Note: You may be tempted to use
# THIS WILL GIVE YOU AN EMPTY FILE!
tail -n +2 "$FILE" > "$FILE"
but this will give you an empty file. The reason is that the redirection (>) happens before tail is invoked by the shell:
- Shell truncates file
$FILE
- Shell creates a new process for
tail
- Shell redirects stdout of the
tail process to $FILE
tail reads from the now empty $FILE
If you want to remove the first line inside the file, you should use:
tail -n +2 "$FILE" > "$FILE.tmp" && mv "$FILE.tmp" "$FILE"
The && will make sure that the file doesn't get overwritten when there is a problem.
Bit of awk should do it?
awk '{s+=$1} END {print s}' mydatafile
Note: some versions of awk have some odd behaviours if you are going to be adding anything exceeding 2^31 (2147483647). See comments for more background. One suggestion is to use printf rather than print:
awk '{s+=$1} END {printf "%.0f", s}' mydatafile
Best Answer
You can do it with
cut:Explanation:
cut: invoke the cut command-d " ": use a single space as the delimiter (cutuses TAB by default)-f: specify fields to keep3-: all the fields starting with field 3input_filename: use this file as the input> output_filename: write the output to this file.Alternatively, you can do it with
awk:Explanation:
awk: invoke the awk command$1=""; $2="";: set field 1 and 2 to the empty stringsub(...);: clean up the output fields because fields 1 & 2 will still be delimited by " "print: print the modified lineinput_filename > output_filename: same as above.