bash shell 编程练习

Posted 2020-08-27 xiluhua

原始文件：

find /etc -name passwd 2>&1 | tee ee.log

 

1. cat -n 把 e.log 的文档内容加上行号后输入 e2.log 这个文档里：

[email protected] ~/t2scripts $ cat -n e.log | tee e2.log
     1  /etc/passwd
     2
     3
     4  find: `/etc/ntp/crypto‘: Permission denied
     5  find: `/etc/audisp‘: Permission denied
     6  find: `/etc/audit‘: Permission denied
     7
     8  find: `/etc/polkit-1/localauthority‘: Permission denied
     9  find: `/etc/dhcp‘: Permission denied
    10  /etc/pam.d/passwd
    11  find: `/etc/lvm/backup‘: Permission denied
    12  find: `/etc/lvm/cache‘: Permission denied
    13  find: `/etc/lvm/archive‘: Permission denied
    14  find: `/etc/cups/ssl‘: Permission denied
    15  find: `/etc/pki/rsyslog‘: Permission denied
    16
    17
    18
    19
    20
    21
    22  find: `/etc/pki/CA/private‘: Permission denied
    23  find: `/etc/vmware-tools/GuestProxyData/trusted‘: Permission denied
    24  find: `/etc/sudoers.d‘: Permission denied
    25  find: `/etc/selinux/targeted/modules/active‘: Permission denied

 

2. cat -b 把 textfile1 和 textfile2 的文档内容加上行号（空白行不加）之后将内容附加到 textfile3 文档里：

[email protected] ~/t2scripts $ cat -b e.log | tee e3.log
     1  /etc/passwd
 
 
     2  find: `/etc/ntp/crypto‘: Permission denied
     3  find: `/etc/audisp‘: Permission denied
     4  find: `/etc/audit‘: Permission denied
 
     5  find: `/etc/polkit-1/localauthority‘: Permission denied
     6  find: `/etc/dhcp‘: Permission denied
     7  /etc/pam.d/passwd
     8  find: `/etc/lvm/backup‘: Permission denied
     9  find: `/etc/lvm/cache‘: Permission denied
    10  find: `/etc/lvm/archive‘: Permission denied
    11  find: `/etc/cups/ssl‘: Permission denied
    12  find: `/etc/pki/rsyslog‘: Permission denied
 
 
 
 
 
 
    13  find: `/etc/pki/CA/private‘: Permission denied
    14  find: `/etc/vmware-tools/GuestProxyData/trusted‘: Permission denied
    15  find: `/etc/sudoers.d‘: Permission denied
    16  find: `/etc/selinux/targeted/modules/active‘: Permission denied

3. cat /dev/null 清空 ee.log 文档内容：

cat /dev/null > e3.log 

 4. chattr  +i：不得任意更动文件或目录。

[email protected] /home/xiluhua/t2scripts $ chattr +i ttt.sh $ 加了 +i 之后，root权限也删不了了
[email protected] /home/xiluhua/t2scripts $ rm -rf ttt.sh 
rm: cannot remove `ttt.sh‘: Operation not permitted

5. chgrp (1)

[email protected] /home/xiluhua/t2scripts # touch ttt.sh
[email protected] /home/xiluhua/t2scripts # ll ttt.sh 
-rw-r--r--. 1 root root 0 Jan 15 15:22 ttt.sh
[email protected] /home/xiluhua/t2scripts # chgrp xiluhua ttt.sh 
[email protected] /home/xiluhua/t2scripts # ll ttt.sh 
-rw-r--r--. 1 root xiluhua 0 Jan 15 15:22 ttt.sh

6. chgrp (2)