linux--character wildcard characters

When we use the command ls to view a directory or file, sometimes we just need to view a specific directory or file, this time we need to use the file name wildcard, also known as the character wildcard.

Special note here, after cd/etc/, go to the ETC directory, when using LS, you need to add the option –d so that the result displays the directory name or file name, does not expand the directory display. Can not be added.

As for the use of the LS command, you can find it yourself.

Next, I'll explain the wildcard characters by example.

1.) *: Used to match 0 or more arbitrary characters

For example, LS * finds files or directories of any character under/etc

[[email protected] etc] # ls-d * 3dkdj                    maven3fgfj                    mime.types3fgfj[]                  mke2fs.conf3jsjdl[]                 modprobe.dabrt                     motdacpi                     mTAB

2.)? : matches any 1 characters, that is, one character matches one character

For example: LS??? Find files or directories with any length of three characters under/etc

[[email protected] etc] # ls-d??? 253  786  Hal  JVM  LVM  opt  PPP  rpm  ssh  X11  xml333  GDM  IPA  KDE  NTP  PKI  RPC  SCL  SSL  xdg  Yum

3.) [0-9]: A [0-9] represents only a number between 0-9

For example: LS [0-9] [1-2][0-9] 3[0-9] Use touch {1..100} to create 1 to 100 of these 100 files, showing 1-35

[[email protected] etc] # ls  [0-9] [1-2][0-9] [3][0-5]1   each  28  3   to  5  7  910  2  23  4   6  8

4.) [A-Z]: Indicates aabbcc......z, unable to display z [A-z]: indicates ABBCC ... Z, unable to display z [A-z]: denotes all uppercase and lowercase letters

Eg: find a file or directory with a length of three that starts with any letter in the/etc directory

[[email protected] etc] # ls-d [A-z]?? GDM  IPA  KDE  NTP  PKI  RPC  SCL  SSL  xdg  yumhal  JVM  LVM  Opt  PPP  rpm  ssh  X11  xml

5.) [AE]: Represents a single character of A or E [^ae]: Indicates that neither a nor E is any other single character

Eg: Show only non-hidden directories in/etc

[[email protected] etc] # ls  -D/[^.] */app   /lib64       /proc     /tmp/bin   /lost+found  /root     /usr/boot  /media       /sbin     /var/dev   /misc        /selinux  /vmwaretools-10.1.6-5214329. tar.gz   /etc/mnt         /srv      /vmware-tools-distrib  /home/net         /sys /lib   /opt         /testdir

Eg: Show only non-hidden directories in the user's home directory

1[[Email protected] ~]#ls-1/home/[^.] *2/home/CentOS:3 Desktop4 Documents5 Downloads6 Music7 Pictures8  Public9 TemplatesTen Videos One  A/home/www:

6.) [: Lower:]: Indicates lowercase letters
[: Upper:]: Uppercase
[: Alpha:]: Indicates uppercase and lowercase letters

Eg: Displays files or directories with a file name that contains at least one lowercase letter and a number and ends with. conf in the/etc directory

(PS: Option-1 to list the result items for LS lookup)

1 [[email protected] ~]#  ls-d1/etc/*[[:lower:]]*[0-9]*.conf2 /etc/  krb5.conf3 /etc/mke2fs.conf4 /etc/pbm2ppa.conf5 /etc/ Pnm2ppa.conf

7.) [:d igit:]: Indicates that any number equals 0-9
[: Alnum:]: Denotes any letter and number equal to a-z0-9 or with [[:d Igit:][:alpha:]] to indicate

Eg: Displays all files or directories that start with an uppercase letter and end with two digits in the/etc directory

1 [[email protected] ~]#  ls-d1/etc/[[:upper:]]*[[:d igit:]][[:d igit:]]2 /etc/ Kdhu67 3 /etc/Ldf884 /etc/S00995 /etc/Sdjfdjg9886 /etc /Sdjfdjg98977 /etc/x11

Eg: Displays a file or directory containing symbols and numbers for the file name in the/var/log directory

1 [[email protected] ~]#  ls-d1  /var/log/*[[:p unct:]]*[[:d igit:]]*  2 /var/log /btmp-20191120 3 /var/log/cron-20191120 4 /var/log/maillog-20191120 5 /var/log/ messages-20191120 6 /var/log/secure-20191120 7 /var/log/spooler-20191120 8 /var/log/ vmware-vgauthsvc.log.0 9 /var/log/xorg.0. Log /var/log/xorg.0. Log.old   /var/log/xorg.9.log

8.) [: blank:]: horizontal white space character
[: Space:]: Horizontal or vertical whitespace character filenames cannot contain carriage returns, so use with [: blank:]: Same effect
9.) [:p UNCT:]: denotes symbol

See examples in usage 7 for instructions on how to use them.

linux--character wildcard characters