模式匹配后打印n个字符

Question

I have line say

jan 02:12:00 YRU QRS : ASP.net Bird
feb 02:12:00 YRU QRS : ASP.net Dog

I want a script to have a pattern search of ASP.NET and print the 10 Characters from it in each line , So that it would involve both Bird and Dog

Thanks

Answer 1

One way using perl :

perl -ne 'm/asp\.net\s+(.{0,10})/i && print "$1\n"' infile

That yields:

Bird
Dog

---

EDIT to explain the syntax of the perl one-liner:

m/.../i tries to match a regular expression with the whole line. The i flag ignores the case. The regular expression is the literal asp.net plus spaces plus any number of characters between 0 and 10 in greedy way. If that succeeds execute the following instruction that prints what matched between parens.

Answer 2

perl -lne 'print $1 if /ASP.net (.{0,10})/'

Answer 3

GNU and BSD greps have a nice extension --only-matching , or -o , which will output only the part of the line you match:

grep -Eio 'asp\.net.{0,10}' <<< 'jan 02:12:00 YRU QRS : ASP.net Bird
feb 02:12:00 YRU QRS : ASP.net Dog'
ASP.net Bird
ASP.net Dog

Bash can do this with its regular expression functionality, though it's probably better if you turn on case-insensitive matching first:

shopt -s nocasematch
while read; do
    if [[ $REPLY =~ asp\.net(.{0,10}) ]]; then
        echo "${BASH_REMATCH[1]}"
    fi
done <<< 'jan 02:12:00 YRU QRS : ASP.net Bird
feb 02:12:00 YRU QRS : ASP.net Dog'
 Bird
 Dog

Answer 4

awk one-liner:

awk -F'ASP\\.net' '{print substr($2,0,10)}' file

Note that this will print 10 chars immediately after ASP.net , which means, starting from the space . if you don't want the space, use the line below:

 awk -F'ASP\\.net ' '{print substr($2,0,10)}' file

Answer 5

Assuming you have the text inside a file "input.txt" the following one-liner will do the job:

cat input.txt | awk '/ASP\.net/ {print substr($0, index($0,"ASP.net") + length("ASP.net"), 10)}'

Explanation:

• On lines that contain the text "ASP.net"
• print 10 characters
• starting right after the location of "ASP.net"

Answer 6

这可能对您有用（GNU sed）：

sed -nr '/.*ASP\.net(.{,10}).*/s//\1/p' file