Find files and text processing
- Define an alias commands into force all users
example: lftps = 'lftp 172.168.0.1/pub'[root@localhost /]# echo "alias lftps='lftp 172.168.0.1/pub'" >> /etc/bashrc [root@localhost /]# source /etc/bashrc [root@localhost /]# alias alias cp='cp -i' alias egrep='egrep --color=auto' alias fgrep='fgrep --color=auto' alias grep='grep --color=auto' alias l.='ls -d .* --color=auto' alias lftps='lftp 172.168.0.1/pub' alias ll='ls -l --color=auto' alias ls='ls --color=auto' alias mv='mv -i' alias rm='rm -i' alias which='alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde' -
Show / etc / passwd file, not to / bin / bash at the end of the line
[root@localhost /]# grep -v "/bin/bash$" /etc/passwd -
Line find / etc / passwd file, contains the two-digit or three-digit
[root@localhost /]# grep "\<[1-9]\{2,3\}\>" /etc/passwd - Display / proc / meminfo file to start with a lowercase or uppercase S lines; implemented in three ways
(1)[root@localhost /]# grep -i '^s' /proc/meminfo (2)[root@localhost /]# grep '^[sS]' /proc/meminfo (3)[root@localhost /]# grep -E "^(s|S)" /proc/meminfo SwapCached: 0 kB SwapTotal: 2097148 kB SwapFree: 2097148 kB Shmem: 7980 kB Slab: 64752 kB SReclaimable: 28244 kB SUnreclaim: 36508 kB - Echo out an absolute path using the path name egrep removed,
similar to the result of performing dirname / etcpasswd of[root@localhost /]# echo "/etc/sysconfig/netscript " | egrep -o '^/.*/' /etc/sysconfig/ - Find ip address in the ifconfig required results show only the IP address
[root@localhost /]# ifconfig | egrep -o '([0-9]{1,3}\.){3}[0-9]{1,3}' 172.20.10.7 255.255.255.240 172.20.10.15 127.0.0.1 255.0.0.0 - vim customized automatic indentation four characters
打开文件/etc/vim/vimrc最后加入，保存 set tabstop=4 set shiftwidth=4 -
Write a script, automatically add three users, and calculate the uid of these three users and
#!/bin/bash id user1 &> /dev/null || useradd user1 id user2 &> /dev/null || useradd user2 id user3 &> /dev/null || useradd user3 user1_id=$(id -u user1) user2_id=$(id -u user2) user3_id=$(id -u user3) id_num=$[$user1_id + $user2_id + $user3_id] echo "The id sum is $id_num" -
find Usage:
Usage:
find [the OPTIONS] [find the opening path] [search criteria] [Processing operation]
find the opening path: Specifies initial search target specific path; default is the current directory;
search criteria: specified search criteria, may be according to file name, size, type, affiliation, permissions, and so the standard; the default is to find all the files in the specified path;
actions: operations on files that meet the search criteria to make, for example, delete and other operations; default output to standard output;
Search Terms:
(1) Find the file name:-name "pattern" -iname "pattern" 支持glob风格的通配符；*, ?, [], [^] -regex pattern：基于正则表达式模式查找文件，匹配是整个路径，而非其名；(2) According to locate files affiliation:
-user USERNAME：查找属主指定用户的所有文件； -group GRPNAME：查找属组指定组的所有文件； -uid UID：查找属主指定的UID的所有文件； -gid GID：查找属组指定的GID的所有文件； -nouser：查找没有属主的文件； -nogroup：查找没有属组的文件；(3) Find the type of file:
-type TYPE： f: 普通文件 d: 目录文件 l：符号链接文件 b：块设备 文件 c：字符设备文件 p：管道文件 s：套接字文件(4) depending on the size of the lookup file:
-size [+|-]#UNIT 常用单位：k, M, G #UNIT：(#-1, #] -#UNIT：[0,#-1] +#UNIT：(#, oo)(5) According to the time stamp to find:
以“天”为单位： -atime [+|-]# #：[#, #-1) -#：(#, 0] +#：(oo, #-1] -mtime -ctime 以“分钟”为单位： -amin -mmin -cmin(6) under the authority find:
-perm [/|-]mode mode：精确权限匹配； /mode：任何一类用户(u,g,o)的权限中的任何一位(r,w,x)符合条件即满足； 9位权限之间存在“或”关系； -mode：每一类用户(u,g,o)的权限中的每一位(r,w,x)同时符合条件即满足； 9位权限之间存在“与”关系；Actions:
-print：输出至标准输出；默认的动作； -ls：类似于对查找到的文件执行“ls -l”命令，输出文件的详细信息； -delete：删除查找到的文件； -fls /PATH/TO/SOMEFILE：把查找到的所有文件的长格式信息保存至指定文件中； -ok COMMAND {} \; ：对查找到的每个文件执行由COMMAND表示的命令；每次操作都由用户进行确认； -exec COMMAND {} \; ：对查找到的每个文件执行由COMMAND表示的命令； 注意：find传递查找到的文件路径至后面的命令时，是先查找出所有符合条件的文件路径，并一次性传递给后面的命令； 但是有些命令不能接受过长的参数，此时命令执行会失败；另一种方式可规避此问题： find | xargs COMMAND - Examples of common usage of the Find:
(1) Find the / var directory subordinate to the main root, and belong to all files or directories group of mail;[root@localhost /]# find /var -user root -a -group mail -ls 5002 0 drwxrwxr-x 2 root mail 224 Aug 13 14:13 /var/spool/mail 3360 152 -rw------- 1 root mail 154132 Jul 19 16:12 /var/spool/mail/root(2) Find / does not belong to any file or directory root, bin or under mysql usr directory;
[root@localhost /]# find /usr -not -user root -a -not -user bin -a -not -user mysql /usr/share/polkit-1/rules.d /usr/libexec/abrt-action-install-debuginfo-to-abrt-cache(3)查找当前系统上没有属或属组，且最近一周内曾被访问过的文件或目录； [root@localhost /]# find / \( -nouser -o -nogroup \) -atime -7 -ls find: ‘/proc/2710/task/2710/fd/6’: No such file or directory find: ‘/proc/2710/task/2710/fdinfo/6’: No such file or directory find: ‘/proc/2710/fd/6’: No such file or directory find: ‘/proc/2710/fdinfo/6’: No such file or directory(4) Find / etc directory greater than 1M and common files for all types of files;
[root@localhost /]# find /etc/ -size +1M -type f -exec ls -lh {} \; -r--r--r--. 1 root root 7.2M Jul 8 17:32 /etc/udev/hwdb.bin -rw-r--r--. 1 root root 3.6M Aug 6 2017 /etc/selinux/targeted/active/policy.kern -rw-r--r--. 1 root root 1.4M Aug 6 2017 /etc/selinux/targeted/contexts/files/file_contexts.bin -rw-r--r--. 1 root root 3.6M Aug 6 2017 /etc/selinux/targeted/policy/policy.30 -rw-r--r--. 1 root root 1.4M Aug 7 2017 /etc/brltty/zh-tw.ctb(5) to find files in the / etc directory of all users do not have write access;
[root@localhost /]# find /etc -not -perm /222 -type f -ls
(6) Find / etc directory has at least file a class of user does not have permission to perform;[root@localhost /]# find /etc/ -not -perm -111 -type f -ls
(7) Find /etc/init.d/ directory, all users have execute permissions, and other users have write access to all files;[root@localhost /]# find /etc -perm -113 -type f -ls