Linux系列:文件相关操作

1.查看文件

cat:查看小文件

more:按空格翻页查看；按Enter行查看；按Q退出

less:按空格翻页查看；按Enter行查看;P往回看；F往后看

head:查看前几行，默认前十行

tail:查看尾几行，默认尾部十行

[root@centos-master test]# less test.txt
[root@centos-master test]# less test.txt
[root@centos-master test]# head test.txt
test!
ot@centos-master ~]# history
    1  2020-10-25 21:03:39
    2  2020-09-17 20:43:52 ls[root@centos-master ~]# history
    1  2020-10-25 21:03:39
    2  2020-09-17 20:43:52 ls
    3  2020-09-17 20:43:54 ls
    4  2020-09-17 20:43:57 cd /
    5  2020-09-17 20:43:58 ls
    6  2020-09-17 20:50:31 cd /
[root@centos-master test]# tail test.txt
  simple, never   always make simple backups

As a special case, cp makes a backup of SOURCE when the force and backup
options are given and SOURCE and DEST are the same name for an existing,
regular file.

GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
For complete documentation, run: info coreutils 'cp invocation'
[root@centos-master test]#

[root@centos-master test]# head -5 test.txt
test!
ot@centos-master ~]# history
    1  2020-10-25 21:03:39
    2  2020-09-17 20:43:52 ls[root@centos-master ~]# history
    1  2020-10-25 21:03:39
[root@centos-master test]# tail -1 test.txt

[root@centos-master test]#

2.移动、重命名：mv

[root@centos-master test]# mkdir testone
[root@centos-master test]# ls
testone
[root@centos-master test]# mv testone/ testtwo
[root@centos-master test]# ls
testtwo
[root@centos-master test]# mkdir dir1
[root@centos-master test]# mv testtwo/ dir1/
[root@centos-master test]# tree
.
`-- dir1
    `-- testtwo

2 directories, 0 files
[root@centos-master test]# mv --help
Usage: mv [OPTION]... [-T] SOURCE DEST
  or:  mv [OPTION]... SOURCE... DIRECTORY
  or:  mv [OPTION]... -t DIRECTORY SOURCE...
Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY.

Mandatory arguments to long options are mandatory for short options too.
      --backup[=CONTROL]       make a backup of each existing destination file
  -b                           like --backup but does not accept an argument
  -f, --force                  do not prompt before overwriting
  -i, --interactive            prompt before overwrite
  -n, --no-clobber             do not overwrite an existing file
If you specify more than one of -i, -f, -n, only the final one takes effect.
      --strip-trailing-slashes  remove any trailing slashes from each SOURCE
                                 argument
  -S, --suffix=SUFFIX          override the usual backup suffix
  -t, --target-directory=DIRECTORY  move all SOURCE arguments into DIRECTORY
  -T, --no-target-directory    treat DEST as a normal file
  -u, --update                 move only when the SOURCE file is newer
                                 than the destination file or when the
                                 destination file is missing
  -v, --verbose                explain what is being done
  -Z, --context                set SELinux security context of destination
                                 file to default type
      --help     display this help and exit
      --version  output version information and exit

The backup suffix is '~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX.
The version control method may be selected via the --backup option or through
the VERSION_CONTROL environment variable.  Here are the values:

  none, off       never make backups (even if --backup is given)
  numbered, t     make numbered backups
  existing, nil   numbered if numbered backups exist, simple otherwise
  simple, never   always make simple backups

GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
For complete documentation, run: info coreutils 'mv invocation'
[root@centos-master test]#

3.硬链接、软连接：ln

ln file1 file2 硬链接

ln -s file1 file2 软链接

目录是不能创建硬链接的

[root@centos-master test]# vim hello.c
[root@centos-master test]# ls
hello.c
[root@centos-master test]# cat hello.c
hello world!
[root@centos-master test]# ln hello.c  hello2.c
[root@centos-master test]# ls
hello2.c  hello.c
[root@centos-master test]# cat hello2.c
hello world!
[root@centos-master test]# ls -l
total 8
-rw-r--r-- 2 root root 13 Dec  8 21:27 hello2.c
-rw-r--r-- 2 root root 13 Dec  8 21:27 hello.c
[root@centos-master test]# touch test.txt
[root@centos-master test]# ls -l
total 8
-rw-r--r-- 2 root root 13 Dec  8 21:27 hello2.c
-rw-r--r-- 2 root root 13 Dec  8 21:27 hello.c
-rw-r--r-- 1 root root  0 Dec  8 21:29 test.txt
[root@centos-master test]# ln hello.c hello3.c
[root@centos-master test]# ls -l
total 12
-rw-r--r-- 3 root root 13 Dec  8 21:27 hello2.c
-rw-r--r-- 3 root root 13 Dec  8 21:27 hello3.c
-rw-r--r-- 3 root root 13 Dec  8 21:27 hello.c
-rw-r--r-- 1 root root  0 Dec  8 21:29 test.txt
[root@centos-master test]# rm  hello3.c
rm: remove regular file ‘hello3.c’? y
[root@centos-master test]# ls -l
total 8
-rw-r--r-- 2 root root 13 Dec  8 21:27 hello2.c
-rw-r--r-- 2 root root 13 Dec  8 21:27 hello.c
-rw-r--r-- 1 root root  0 Dec  8 21:29 test.txt
[root@centos-master test]# cat hello2.c
hello world!
[root@centos-master test]# vim hello2.c
[root@centos-master test]# cat hello.c
test hello world!
[root@centos-master test]# cat hello2.c
test hello world!
[root@centos-master test]#

4.查看文件信息：wc、od、du、df

od:查看二进制文件的信息

wc：查看普通文件的信息

第一个代表的是行第二代表的是数目以空格为分第三个代表的是字节数

[root@centos-master test]# wc test.txt
 2  9 19 test.txt
[root@centos-master test]# cat test.txt
1 2 3 4 55 6
2 2 3

du:查看当前目录的信息加上-h才能看懂

[root@centos-master test]# du
8       .
[root@centos-master test]# tree
.
`-- test.txt

0 directories, 1 file
[root@centos-master test]# du -h
8.0K    .
[root@centos-master test]#

df:磁盘的使用量

[root@centos-master test]# df
Filesystem     1K-blocks    Used Available Use% Mounted on
devtmpfs          929552       0    929552   0% /dev
tmpfs             941072      48    941024   1% /dev/shm
tmpfs             941072     732    940340   1% /run
tmpfs             941072       0    941072   0% /sys/fs/cgroup
/dev/vda1       51473868 6327512  42949112  13% /
tmpfs             188216       0    188216   0% /run/user/0
[root@centos-master test]# df -h
Filesystem      Size  Used Avail Use% Mounted on
devtmpfs        908M     0  908M   0% /dev
tmpfs           920M   48K  919M   1% /dev/shm
tmpfs           920M  732K  919M   1% /run
tmpfs           920M     0  920M   0% /sys/fs/cgroup
/dev/vda1        50G  6.1G   41G  13% /
tmpfs           184M     0  184M   0% /run/user/0
[root@centos-master test]#

5.命令解析器：which

只能查看一些外部的命令

[root@centos-master test]# which cp
alias cp='cp -i'
        /usr/bin/cp
[root@centos-master test]# which ls
alias ls='ls --color=auto'
        /usr/bin/ls
[root@centos-master test]# which cd
/usr/bin/cd
[root@centos-master test]#