[one Linux command per day] linux commands ls and cp

Posted by mourisj on Thu, 06 Jan 2022 16:10:33 +0100

ls (list files) command is used to display the list of file directories, which is similar to the DOS command dir under Windows system. When executing ls command, only the file name of non hidden file, sorting by file name and the color represented by file name are displayed by default. When no parameters are added, the list information of the current directory is listed by default. The ls command is used frequently and has many parameters, up to forty or fifty. This article only introduces some common parameters. For other parameters, you can view the help manual through the man command.

Note: under linux, the file name is dotted The beginning indicates that the file is hidden, such as bashrc.

ls command syntax

ls [option] [Directory or file name]

Parameters:
-a: --all Display all files, including hidden files(with.Start file)，Refer to example 1.(Commonly used)
-A: --almost-all The abbreviation of shows all files, including hidden files, but excluding the current directory.And parent directory..For these two documents, refer to example 2.
-c: and-lt Use together: displays a list and displays it in ctime(Last change time of file status)Sort. and-l Use with: display ctime And sorted by file name. Other cases, to ctime Sort. Refer to example 3.
-d: --directory For the abbreviation of, only the directory itself is listed, not the list of contents in the directory. Refer to example 4.(Commonly used)
-f: List the results directly without sorting(ls Sort by file name by default)
--color[=WHEN]: Whether to display color according to file type, WHEN Can be never,always perhaps auto
--full-time: Display in full actual mode(Including mm / DD / yyyy)，Similar to ls -l --time-style=full-iso，Refer to example 5.
-g: List display results, and-l Similar, but the owner of the file is not displayed.
-h: Change the file content size to GB,KB And so on, refer to example 6.
-i: combination-l Parameter that lists the of each file inode，Refer to example 7.
-l: List long data strings and display data information such as file attributes and permissions(Commonly used)
-n: and-l Similarly, only the displayed users and groups are not names, but corresponding id，Refer to example 8.
-r: --reverse，Display the sorting results in reverse order, refer to Example 9.
-S: Sort by file size, refer to Example 9.
-t: Sort by modified time
--help: display help information

ls command example

[centos@s202 ~]$ ls
1.log      a.txt       coprocessor.log  filename.txt  for99.sh  hadoop-2.7.3.tar.gz  ini                         log        student.txt  test4.sh  tf.sh
1.txt      caseeg.sh   file             file.out      ha        hadoop.txt           jdk-8u131-linux-x64.tar.gz  logs       test2.sh     test5.sh  zookeeper
anaconda3  color99.sh  file.err         for99         hadoop    header.txt           kafka                       logZip.sh  test3.sh     test.sh   zookeeper.out

Example 1: list all files (note the difference with the - A parameter. The result includes the two files representing the current directory. And the parent directory.

[centos@s202 ~]$ ls -a
.      anaconda3      .bash_profile          color99.sh       file.err      for99     hadoop-2.7.3.tar.gz  jdk-8u131-linux-x64.tar.gz  logZip.sh          student.txt  test5.sh   zookeeper.out
..     a.txt          .bashrc                .continuum       filename.txt  for99.sh  hadoop.txt           kafka                       .oracle_jre_usage  test2.sh     test.sh
1.log  .bash_history  .bashrc-anaconda3.bak  coprocessor.log  file.out      ha        header.txt           log                         .python_history    test3.sh     tf.sh
1.txt  .bash_logout   caseeg.sh              file             .flume        hadoop    ini                  logs                        .ssh               test4.sh     zookeeper

Example 2: list all files, but not the current directory And parent directory These two documents.

[centos@s202 ~]$ ls -A
1.log      .bash_history  .bashrc-anaconda3.bak  coprocessor.log  file.out  ha                   header.txt                  log                .python_history  test3.sh  tf.sh
1.txt      .bash_logout   caseeg.sh              file             .flume    hadoop               ini                         logs               .ssh             test4.sh  zookeeper
anaconda3  .bash_profile  color99.sh             file.err         for99     hadoop-2.7.3.tar.gz  jdk-8u131-linux-x64.tar.gz  logZip.sh          student.txt      test5.sh  zookeeper.out
a.txt      .bashrc        .continuum             filename.txt     for99.sh  hadoop.txt           kafka                       .oracle_jre_usage  test2.sh         test.sh

[centos@s202 ~]$ ls --almost-all
1.log      .bash_history  .bashrc-anaconda3.bak  coprocessor.log  file.out  ha                   header.txt                  log                .python_history  test3.sh  tf.sh
1.txt      .bash_logout   caseeg.sh              file             .flume    hadoop               ini                         logs               .ssh             test4.sh  zookeeper
anaconda3  .bash_profile  color99.sh             file.err         for99     hadoop-2.7.3.tar.gz  jdk-8u131-linux-x64.tar.gz  logZip.sh          student.txt      test5.sh  zookeeper.out
a.txt      .bashrc        .continuum             filename.txt     for99.sh  hadoop.txt           kafka                       .oracle_jre_usage  test2.sh         test.sh

Example 3: display the list and sort by ctime

[centos@s202 ~]$ ls -clt
total 390824
-rw-rw-r--.  1 centos centos        65 May 23 14:59 1.log
-rw-rw-r--.  1 centos centos       157 May 23 14:59 test5.sh
-rw-rw-r--.  1 centos centos       205 May 23 11:27 logZip.sh
-rw-rw-r--.  1 centos centos       108 May 23 11:15 test4.sh
-rw-rw-r--.  1 centos centos       139 May 23 09:15 ini
-rw-rw-r--.  1 centos centos       268 May 23 01:16 test3.sh
-rw-rw-r--.  1 centos centos        51 May 21 17:38 filename.txt
-rw-rw-r--.  1 centos centos         1 May 21 17:38 file.err
-rw-rw-r--.  1 centos centos         1 May 21 17:37 file.out
-rw-rw-r--.  1 centos centos        51 May 21 17:30 a.txt
-rw-rw-r--.  1 centos centos        56 May 21 16:33 test.sh
-rw-rw-r--.  1 centos centos         5 May 21 14:39 file
-rw-rw-r--.  1 centos centos         8 Apr  5 01:18 test2.sh
drwxrwxr-x.  3 centos centos        35 Apr  5 01:03 zookeeper
-rw-rw-r--.  1 centos centos    474970 Apr  5 01:03 zookeeper.out
drwxrwxr-x. 12 centos centos       150 Jan 26 17:06 anaconda3
drwxrwxr-x.  3 centos centos        18 Nov  2  2018 kafka
drwxrwxr-x.  4 centos centos        37 Oct 11  2018 ha
-rw-rw-r--.  1 centos centos         4 Aug 24  2018 student.txt
drwxrwxr-x.  2 centos centos        63 Aug 24  2018 log
drwxrwxr-x.  2 centos centos         6 Aug 24  2018 logs
-rw-rw-r--.  1 centos centos        10 Aug 24  2018 header.txt
-rw-rw-r--.  1 centos centos       219 Aug 18  2018 coprocessor.log
drwxrwxr-x.  4 centos centos        37 Jul 22  2018 hadoop
-rw-rw-r--.  1 centos centos      1060 Jul 20  2018 hadoop.txt
-rw-rw-r--.  1 centos centos 214092195 Jul 20  2018 hadoop-2.7.3.tar.gz
-rwxrwxr-x.  1 centos centos        86 Jul 17  2018 caseeg.sh
-rwxrw-r--.  1 centos centos        90 Jul 17  2018 color99.sh
-rwxrwxr-x.  1 centos centos        53 Jul 17  2018 tf.sh
-rwxrwxr-x.  1 centos centos       140 Jul 17  2018 for99.sh
-rwxrwxr-x.  1 centos centos       108 Jul 17  2018 for99
-rw-rw-r--.  1 centos centos        20 Jul 17  2018 1.txt
-rw-rw-r--.  1 centos centos 185540433 Jul 17  2018 jdk-8u131-linux-x64.tar.gz

[centos@s202 ~]$  ls -cl
total 390824
-rw-rw-r--.  1 centos centos        65 May 23 14:59 1.log
-rw-rw-r--.  1 centos centos        20 Jul 17  2018 1.txt
drwxrwxr-x. 12 centos centos       150 Jan 26 17:06 anaconda3
-rw-rw-r--.  1 centos centos        51 May 21 17:30 a.txt
-rwxrwxr-x.  1 centos centos        86 Jul 17  2018 caseeg.sh
-rwxrw-r--.  1 centos centos        90 Jul 17  2018 color99.sh
-rw-rw-r--.  1 centos centos       219 Aug 18  2018 coprocessor.log
-rw-rw-r--.  1 centos centos         5 May 21 14:39 file
-rw-rw-r--.  1 centos centos         1 May 21 17:38 file.err
-rw-rw-r--.  1 centos centos        51 May 21 17:38 filename.txt
-rw-rw-r--.  1 centos centos         1 May 21 17:37 file.out
-rwxrwxr-x.  1 centos centos       108 Jul 17  2018 for99
-rwxrwxr-x.  1 centos centos       140 Jul 17  2018 for99.sh
drwxrwxr-x.  4 centos centos        37 Oct 11  2018 ha
drwxrwxr-x.  4 centos centos        37 Jul 22  2018 hadoop
-rw-rw-r--.  1 centos centos 214092195 Jul 20  2018 hadoop-2.7.3.tar.gz
-rw-rw-r--.  1 centos centos      1060 Jul 20  2018 hadoop.txt
-rw-rw-r--.  1 centos centos        10 Aug 24  2018 header.txt
-rw-rw-r--.  1 centos centos       139 May 23 09:15 ini
-rw-rw-r--.  1 centos centos 185540433 Jul 17  2018 jdk-8u131-linux-x64.tar.gz
drwxrwxr-x.  3 centos centos        18 Nov  2  2018 kafka
drwxrwxr-x.  2 centos centos        63 Aug 24  2018 log
drwxrwxr-x.  2 centos centos         6 Aug 24  2018 logs
-rw-rw-r--.  1 centos centos       205 May 23 11:27 logZip.sh
-rw-rw-r--.  1 centos centos         4 Aug 24  2018 student.txt
-rw-rw-r--.  1 centos centos         8 Apr  5 01:18 test2.sh
-rw-rw-r--.  1 centos centos       268 May 23 01:16 test3.sh
-rw-rw-r--.  1 centos centos       108 May 23 11:15 test4.sh
-rw-rw-r--.  1 centos centos       157 May 23 14:59 test5.sh
-rw-rw-r--.  1 centos centos        56 May 21 16:33 test.sh
-rwxrwxr-x.  1 centos centos        53 Jul 17  2018 tf.sh
drwxrwxr-x.  3 centos centos        35 Apr  5 01:03 zookeeper
-rw-rw-r--.  1 centos centos    474970 Apr  5 01:03 zookeeper.out

Example 4: only the directory itself is listed, and there is no need to list the contents in the directory

[centos@s202 ~]$ ls -d /home   #Only the / home directory itself is listed
/home
[centos@s202 ~]$ ls /home   #List the contents of the / home directory
centos

Example 5: display full time

[centos@s202 ~]$ ls --full-time /
total 20
lrwxrwxrwx.   1 root   root      7 2018-07-16 22:14:25.675333601 +0800 bin -> usr/bin
dr-xr-xr-x.   4 root   root   4096 2018-07-16 22:20:27.271001648 +0800 boot
drwxr-xr-x.  20 root   root   3180 2019-05-24 20:32:14.446999702 +0800 dev
drwxr-xr-x.  78 root   root   8192 2019-05-24 20:32:06.675999960 +0800 etc
drwxr-xr-x.   3 root   root     20 2018-07-16 22:18:42.624343276 +0800 home
lrwxrwxrwx.   1 root   root      7 2018-07-16 22:14:25.677333601 +0800 lib -> usr/lib
lrwxrwxrwx.   1 root   root      9 2018-07-16 22:14:25.677333601 +0800 lib64 -> usr/lib64
drwxr-xr-x.   2 root   root      6 2016-11-05 23:38:36.000000000 +0800 media
drwxr-xr-x.   2 root   root      6 2016-11-05 23:38:36.000000000 +0800 mnt
drwxr-xr-x.   2 root   root     45 2019-01-26 17:08:03.622231114 +0800 opt
dr-xr-xr-x. 156 root   root      0 2019-05-24 20:31:59.011000000 +0800 proc
dr-xr-x---.   7 root   root    209 2018-08-31 14:37:12.818765051 +0800 root
drwxr-xr-x.  21 root   root    600 2019-05-24 20:32:26.359999305 +0800 run
lrwxrwxrwx.   1 root   root      8 2018-07-16 22:14:25.677333601 +0800 sbin -> usr/sbin
drwxr-xr-x.  10 centos centos 4096 2018-10-09 15:46:23.455045955 +0800 soft
drwxr-xr-x.   2 root   root      6 2016-11-05 23:38:36.000000000 +0800 srv
dr-xr-xr-x.  13 root   root      0 2019-05-24 20:32:07.496999933 +0800 sys
drwxrwxrwt.   7 root   root     93 2019-05-24 21:31:02.252882289 +0800 tmp
drwxr-xr-x.  13 root   root    155 2018-07-16 22:14:25.839333607 +0800 usr
drwxr-xr-x.  19 root   root    267 2019-05-24 20:32:06.676999960 +0800 var

Example 6: display a list in a readable manner

[centos@s203 ~]$ ls -l
total 524
drwxrwxr-x. 12 centos centos    150 Jan 26 17:17 anaconda3
drwxrwxr-x.  4 centos centos     37 Oct 11  2018 ha
drwxrwxr-x.  4 centos centos     37 Jul 22  2018 hadoop
drwxrwxr-x.  3 centos centos     18 Nov  2  2018 kafka
drwxrwxr-x.  2 centos centos     19 Aug 23  2018 log
drwxrwxr-x.  2 centos centos     21 Aug 24  2018 logs
drwxrwxr-x.  3 centos centos     56 Apr  5 01:03 zookeeper
-rw-rw-r--.  1 centos centos 534884 Apr  5 01:03 zookeeper.out
[centos@s203 ~]$ ls -lh
total 524K
drwxrwxr-x. 12 centos centos  150 Jan 26 17:17 anaconda3
drwxrwxr-x.  4 centos centos   37 Oct 11  2018 ha
drwxrwxr-x.  4 centos centos   37 Jul 22  2018 hadoop
drwxrwxr-x.  3 centos centos   18 Nov  2  2018 kafka
drwxrwxr-x.  2 centos centos   19 Aug 23  2018 log
drwxrwxr-x.  2 centos centos   21 Aug 24  2018 logs
drwxrwxr-x.  3 centos centos   56 Apr  5 01:03 zookeeper
-rw-rw-r--.  1 centos centos 523K Apr  5 01:03 zookeeper.out
[centos@s203 ~]$

Example 7: displaying inode s

[centos@s203 ~]$ ls -li /
total 20
      95 lrwxrwxrwx.   1 root   root      7 Jul 16  2018 bin -> usr/bin
      64 dr-xr-xr-x.   4 root   root   4096 Jul 16  2018 boot
    1025 drwxr-xr-x.  20 root   root   3180 May 27 11:29 dev
16777281 drwxr-xr-x.  78 root   root   8192 May 27 11:29 etc
50331740 drwxr-xr-x.   3 root   root     20 Jul 16  2018 home
      98 lrwxrwxrwx.   1 root   root      7 Jul 16  2018 lib -> usr/lib
      82 lrwxrwxrwx.   1 root   root      9 Jul 16  2018 lib64 -> usr/lib64
      83 drwxr-xr-x.   2 root   root      6 Nov  5  2016 media
16777649 drwxr-xr-x.   2 root   root      6 Nov  5  2016 mnt
33575378 drwxr-xr-x.   2 root   root     45 Jan 26 16:48 opt
       1 dr-xr-xr-x. 154 root   root      0 May 27 11:29 proc
33574977 dr-xr-x---.   7 root   root    213 Jan 26 17:15 root
    9241 drwxr-xr-x.  21 root   root    600 May 27 11:30 run
      99 lrwxrwxrwx.   1 root   root      8 Jul 16  2018 sbin -> usr/sbin
33575338 drwxr-xr-x.  10 centos centos 4096 Oct  9  2018 soft
50331741 drwxr-xr-x.   2 root   root      6 Nov  5  2016 srv
       1 dr-xr-xr-x.  13 root   root      0 May 27 11:29 sys
16777288 drwxrwxrwt.   7 root   root     93 May 27 12:48 tmp
33575353 drwxr-xr-x.  13 root   root    155 Jul 16  2018 usr
50331713 drwxr-xr-x.  19 root   root    267 May 27 11:29 var

The Linux cp (copy file) command is mainly used to copy files or directories.

cp command syntax

cp [options] source dest

or

cp [options] source... directory

Parameter Description:

  • -a: This option is usually used when copying a directory. It retains links, file properties, and copies everything under the directory. Its function is equal to dpR parameter combination.
  • -d: Keep links when copying. The links mentioned here are equivalent to shortcuts in Windows system.
  • -f: Overwrite the existing target file without prompting.
  • -i: Contrary to the - f option, a prompt is given before overwriting the target file to ask the user to confirm whether to overwrite. When you answer y, the target file will be overwritten.
  • -p: In addition to copying the contents of the file, the modification time and access rights are also copied to the new file.
  • -r: If the given source file is a directory file, all subdirectories and files in the directory will be copied.
  • -l: Do not copy files, just generate linked files.

-a. -- archive equals - dR --preserve=all --backup[=CONTROL create a backup for each existing target file

-b similar - backup but does not accept the parameter -- copy contents copies the contents of special files in recursive processing

-d equals – no dereference -- preserve = links

-f. -- force if the target file cannot be opened, remove it and try again (do not select this option when the - n option exists)

-i. -- interactive ask before overwriting (invalidates the previous - n option)

-H follows the command line symbolic link in the source file

-l. -- link link file without copying

-50. -- dereference always follows symbolic links

-n. -- no clobber do not overwrite existing files (invalidate the previous - i option)

-P. -- no dereference does not follow symbolic links in the source file

-p equals – preserve = mode, ownership, timestamp -- preserve [= the attribute list maintains the specified attributes (default: mode, ownership, timestamp), and if possible, additional attributes: environment, link, xattr, etc

-R. - R, -- recursive copy the directory and all items in the directory

cp command example

1, Copy a source file to a destination file (folder).

The command format is: cp source file destination file (folder)

This is the most frequently used command, which is responsible for copying a source file to the target file (folder). As shown in the following figure, if you copy to a folder, the file name will remain unchanged, and if you copy to a file, the file name will change. If the target file already exists or the target folder contains a file with the same name, the target file or the file with the same name in the target folder will be overwritten after copying.

The cp command copies a file

2, Copy multiple files to the target file (folder) at the same time.

The command format is: cp source file 1 source file 2 destination folder or cp file * destination folder

This command is also used frequently. The first command format can copy multiple listed files to the target folder at one time, and each file is directly separated by a space; The second command format uses wildcard *, as shown in the following figure. You can copy all files ending in ". txt" to the folder testDir.

The cp command copies multiple files

The cp command copies multiple files

3, Copy the source folder to the destination folder.

The command format is: cp -r source folder destination folder

This is also a frequently used command. Just remember to add "- r" parameter to copy folders, otherwise "CP: submitting directory" error will appear.

Copy folder with cp command

4, Copy only if the source file is newer than the destination file.

The command format is: cp -u source file destination file

This command is useful, especially when updating files. As shown in the figure below, the source file will be copied to the target file only when the source file is newer than the target file. Otherwise, the command will not be copied if it is executed in time.

The cp command copies only when the file is newer

5, Create a soft link to the file.

The command format is: cp -s source file destination file

You can also use the ln command to achieve the same function. When a file path is too deep (such as a/b/c/d/e/orginalFile.txt below) and it is very inconvenient to access, a soft link to the file will be created to make it easier to access. Soft links are equivalent to shortcuts on windows.

The cp command creates a soft link

6, Create a hard link to the file.

The command format is: cp -l source file destination file

You can also use the ln command to achieve the same function. Sometimes, for some reason, you need to create a hard link, as shown in the following figure.

The cp command creates a hard link

Here is a brief introduction to the difference between hard link and soft link. As shown in the following figure, the inodes of the soft link file (softLink.txt) and the linked file (orginalFile.txt) are different (133827 and 139819), and the hard link file (hardLink.txt) and the linked file (orginalFile22.txt) have the same inodes (156981). When the linked file is deleted, the soft link file cannot be accessed, while the hard link file can still be accessed normally.

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