如何从shell bash中的文本文件中提取模式

Question

I have a text file that contains:

toto.titi.any=val1
toto.tata.any=val2
toto.tete.any=val2

How to extract titi , tata and tete from this file.

Should be some sthing like that

$ cat myfile.txt | sed '......' 

and the output should be

titi
tata
tete

Answer 1

Do you really need sed ? You could use cut :

cut -d. -f2 filename

Answer 2

使用awk你可以做到：

awk -F. '{print $2}' file

Answer 3

awk/cut would be better choice for this problem.

here is the sed line and grep option:

sed -r 's/.*\.([^.]*)\..*/\1/'
grep -Po '\.\K[^.]*(?=\.)' 

Answer 4

awk and cut are best for this

you can also read the file line by line, and print out the portion needed.

$ IFS=.
$ while read first interested others ; do echo $interested; done < file
titi
tata
tete

Answer 5

sed -n 's/^[^.]*.\([^.]*\)..*/\1/p' myfile.txt

显示内部至少有2个点的线之间的第二个值