sorting

Shell Programming and Scripting
1

Hii guys,
I need to sort my file and remove duplicates before writing to another file. The first line in the file are column names. I dont want this line to be sorted and should always be the first line in the output.

sort -u file.txt > file1.txt. is the command that i am using because of which the column name is comming last.

sorting by descending order might help. But i dont know which command to use

thanks for your help

2

Alas, sort doesn't know how to skip lines. You must extract the first line separately, then sort the rest, then add it back later:

{ head -1 file.txt ; tail +2 file.txt | sort -u ; } >file1.txt

The tail +2 extracts the file starting from the 2nd line. You can "group" the output of all the commands contained within curly-braces.

1 Like
3

There's no need for head or tail:

{
 IFS= read -r line
 printf "%s\n" "$line"
 sort -u
} < "$file" > "$newfile"
1 Like
4 
awk 'NR==1{print;next} {print |"sort -u"}' infile
5 
 $ ruby -e 'a=open("file").read.split("\n"); puts a[0];puts a[1..-1].sort.uniq' > newfile