awk 截取字段

jason680

回复 1# cwd0204


-7 +1 = -6

$ echo abcdefghi | awk 'function get7(str){return(substr(str,length(str)-6))}{print get7($0)}'
cdefghi

$ echo 123456789 | awk 'function get7(str){return(substr(str,length(str)-6))}{print get7($0)}'
3456789

过过招

awk '{print substr($NF,-7,7)}' file1.txt

jason680

回复 3# cwd0204

other idea

$ echo 123456789 | awk 'function getn(str,n){if(n<0)return(substr(str,length(str)+n+1));return(substr(str,1,n))}{print getn($0,5)}'
12345

$ echo 123456789 | awk 'function getn(str,n){if(n<0)return(substr(str,length(str)+n+1));return(substr(str,1,n))}{print getn($0,-5)}'
56789

$ echo 123456789 | awk 'function getn(str,n){if(n<0)return(substr(str,length(str)+n+1));return(substr(str,1,n))}{print getn($0,3)}'
123

$ echo 123456789 | awk 'function getn(str,n){if(n<0)return(substr(str,length(str)+n+1));return(substr(str,1,n))}{print getn($0,-3)}'
789

csccyab

# echo "GO Order 1577365" | sed 's/.*\(.\{7\}\)/\1/'
1577365