WILDCARD "?": its meaning is one character in Linux.
Example,
[root@localhost root]# ls cool?
cool1 cool0 coolA coolz
ð It is showing the files, which file's name is started with "cool" and next one character may be a, b, c ...., z or 0, 1, 2, ... 9 etc.
Example,
[root@localhost root]# ls local??
local12 localab
Example,
[root@localhost root]# ls cool.?
cool.a cool.1 cool._
ð Showing those files’ name while the extension of each file is single character.
Example,
[root@localhost root]# ls ?.?
a.c b.c j.c
WILDCARD "*": its meaning is more characters in Linux.
Example,
[root@localhost root]# ls *open
firstopen secondopen oldopen
ð Showing those files’ name while last four characters of files are "open".
Example,
[root@localhost root]# ls *mail*
sumonmail1 sumonmail2 azgarmail1
ð Showing those files’ name which has four characters, "mail" is in middle.
[root@localhost root]# ls sumon.*
sumon.sh sumon.cpp sumon.c
ð Showing those files’ name which is "sumon" and can be any extension.
Example,
[root@localhost root]# ls *.*
ð It shows all files those have an extension from the current directory.
[root@localhost root]# ls *
ð It shows all files from the current directory.
WILDCARD "[ ]":
Consider, in /root directory has following files and we can select different file or files to access by using wildcard “-”.
[root@localhost root]# ls
edit1 edit2 edit3 ... ... ... ... edit9
edita editb editc ... ... ... ... editz
edit$ edit@ edit_ ... ... ... ...
Example,
[root@localhost root]# ls edit[123]
edit1 edit2 edit3
Example,
[root@localhost root]# ls edit[^123]
ð It shows all files except edit1, edit2, and edit3.
Example,
[root@localhost root]# ls edit[0-9]
edit0 edit1 edit2 edit3 edit4 edit5 edit6 edit7 edit8 edit9
Example,
[root@localhost root]# ls edit[a-z]
edita editb editc ... ... ... ... editz
Example,
[root@localhost root]# ls edit[^0-9 a-z]
edit$ edit@ edit_
Note: We can also utilize this above wildcards (? , * , [ ]) with other commands, such as cp, mv, rv etc
