Linux Common Command Quick check

1. Recursively query a file containing a string in the specified folder (the file content fragment listed)

grep-r "string to find" file path

such as: Grep-r "HelloWorld". #在当前目录下递归查找 "HelloWorld" string

2. recursively find file names (list file names)

such as: Find. -name "*.log" #在当前目录中递归列出以log为扩展名的文件

3 . Viewing the number of operating system bits

Arch

4. String Simple intercept operation

such as: str= "Com.baidu.android.lulei"

　　1. Get the tail of a string

${str##*.} Get "Lulei" (# #最大限度截取 *.)

${str#*.} Get "Baidu.android.lulei" (#最小限度截取 *.)

${str##*l} get "ei" (Maximum intercept *l)

　2. Get the header of a string

　　　${str%%.*} get "com"(percent of maximum intercept *.)

　　　　${str%.*} get "com.baidu.android"(% minimum intercept *.)

　　　　${str%%.i*} get "com.ba"(maximum intercept *l)

　　3. Specify location acquisition

　　　　${str:0:3} get "com" (3 characters from 1th bit)

${str:4} Get "Baidu.android.lulei" (starting from 5th intercept to end)

${STR:0-5} Get "Lulei" (Intercept from the bottom 5th to the end)

${str:0-5:5} Get "Lulei" (5 bits starting from the 5th digit)

Linux Common Command Quick check