mongo shell commands

Shell learning notes (1) key concepts and commands in shellVariable variableName = value There cannot be spaces around the equal sign The variable content must be enclosed by space, but v = "hello $ name" $ does not support the original function. It cannot be enclosed in single quotes. v = "hello '$ name'" is plain text. Escape Character \ converts special characters into common text 'COMMAND ', $ (comm

Online troubleshooting commands-Shell, online troubleshooting-shell Creation: Liu Xinyu, latest modification: about 4 hours ago Go to metadata start 1. Track online logs and regularly refresh the latest content tail-fn 200 $log 2. Search for a specified string # Show only matching rowsgrep$String $file# Match up or down n rows of the row

2 3 Do For var2 in 0 5 Do if [ $var 1 -eq 2-a $var 2 -eq 0 ] /c0> Then break 2 Else Echo "$var 1 $var 2" fi Done Done As above, break 2 means to jump out of the outer loop directly. Operation Result:1 01 5Continue commandThe continue command is similar to the break command, with only a little difference, and it does not jump out of all loops and just jumps out of the current loop.To modify the above example: #!/bin/bash While : Do echo- n "Input a num

Use shell commands to operate databases and shell command Databases You can use the-e parameter of mysql to perform various SQL operations (create, delete, add, delete, modify, and query ).Usage Mysql-uxxx-pxxx-e "mysql Command" You can also use the following statement: Mysql-e-uxxx-pxxx "mysql Command"Practice [Root @ iZwz99qnmldt4n744noo9gZ ~] # Mysql-e

1. Show the top 10 processes consuming memory/cpu Copy Code code as follows: PS aux | Sort-nk +4 | Tail PS aux | Sort-nk +3 | Tail 2. View process Arrange by memory from large to small Copy Code code as follows: PS-E-O "%c:%p:%z:%a" |sort-k5-nr 3. By CPU utilization from large to small arrangement Copy Code code as follows: PS-E-O "%c:%p:%z:%a" |sort-nr 3. View the number of concurrent requests for Apache and its TCP connect

During the loop, there are times when you need to force out of the loop without reaching the end of the loop, and the shell uses two commands to implement the function: Break and continue. Break command The break command allows you to jump out of all loops (terminating all loops after execution). In the following example, the script goes into a dead loop until the user enters a number greater than 5. To

The shell script reads data in several ways:1. keyboard input, default2. read from the file3. Pass through Pipeline command Functions of Echo:\c: No Line change\f: Paper Feed\ t: the jump Grid\ n: Wrapping Line\ represents escape, for example: "\"/dev/rmt0 "\" translates to, "/dev/rmt0" READ: Reads information from a line of text in a keyboard or file and assigns it to a variable. Copy Code code as follows: [Jb51]/>read Name Hello I

10.1 Commond: Suppress normal shell function lookups 10.2 exec: Replacing the current shell process with the Execute command 10.3 Bash:gnu's Bourne-again shell interpreter 10.4 Builtin: Execute shell built-in command 10.5 Enable: Enables or disables built-in shell