Shell

Output Effect Format control:\033[0m Turn off all properties\033[1m Set High brightness\03[4m Underline\033[5m Flashing\033[7M Reverse Display\033[8m Hidden\033[30m--\033[37m set foreground color\033[40m--\033[47m Set background color Format

Spark-shell-Initiated problem solving Today in the start of the Spark-shell model of the wonderful appearance of the following several problems 1 Port occupancy: 4040 Port is occupied, we know that 4040 is the worker's port use, but is occupied, as

Enter HBase Shell Console $HBASE _home/bin/hbase Shell If you have Kerberos authentication, you need to use the appropriate keytab for authentication (using the Kinit command), and then use the HBase shell after the authentication is successful. You

File expression-e filename true if filename exists-d filename If filename is a directory, true-F filename True if filename is a regular file-L filename True if filename is a symbolic link-r filename If filename is readable, true-W filename if

Shell IntroductionThe shell is a program written in C and a bridge for users to use Linux. The shell is both a command language and a programming language.Shell script, a scripting program written for the shell.Shell Environment The Bourne

Implementation scenario: 1. Add:& at the end of the command#/bin/Bashall_num=Tena=$(Date+%h%m%S) forNuminch`seq 1${all_num} ' Do { Sleep 1 Echo${num}}& Doneb=$(Date+%h%m%S)Echo-E"starttime:\t$a"Echo-E"endtime:\t$b"With the & symbol at the end

WC StatisticsThe number of words, lines, and characters in the file. WC syntax [Root @ WWW ~] #WC[-LWM] Options and parameters:-L: only list rows;-W: Only the number of words listed (one English word );-M: The number of characters;   WC

Fork Usage: fork/directory/script. Sh Fork is the most common. It uses/directory/script. Sh directly in the script to call the script. Sh script. Run a sub-shell script to execute the call. When Sub-shell is executed, parent-shell is still

Trap allows you to capture signals in the script. The common form of this command is: Trap name signal (s) Among them, name is a sequence of operations taken after the captured signal. In real life, name is generally a function specifically used

From: http://standalone.javaeye.com/blog/511101   1. Use the shell variable $ randomEcho $ random 2. Use Random Functions of awkAwk 'in in {srand (); print rand ()}' 3. Use the System Device File/dev/random and/dev/urandomDd If =/dev/random | OD-

-B. returns true if the file exists and is a block file. -C: returns true if the file exists and is a character file. -D. If pathname exists and is a directory, true is returned. -E: returns true if the file or directory specified by

Shelll basic programming theory and some examples   Abstract: This article describes how to compile a shell script based on a large number of instances. (13:27:24) Why shell programming? In Linux, although there are various graphical interface

Problem: It is necessary to pre-process a file of several GB and tens of millions of lines. Function: splits records in a file into different files according to certain rules. Advantage: It is really convenient to use shell scripts for text

Several Popular Shells Currently, popular shell types include ash, Bash, KSh, CSH, and zsh. You can use the following command to view your own shell types:# Echo $ Shell$ Shell is an environment variable that records the shell type used by the user.

Standard Input and Output When executing a shell command line, three standard documents (stdin) are automatically opened, which usually correspond to the keyboard of the terminal. stdout) and stderr correspond to the terminal screen. The process

The following is the shell code: Create_xml.sh #! /Bin/bash # Author: dengzhaoqun # Date: 201202/14 OUTFILE = outtabs = 0put () {echo ' $ OUTFILE} put_head () {put '? '$ {1 }'? '} Out_tabs () {TMP = 0 tabsstr = "" While [$ TMP-lt $ (tabs)]

Publicc void setalpha (INT alpha)Alpha range: 0 ~ 255 This method is supported from eclipse3.4. /*** Sets the operator's Alpha value which must be* Between 0 (transparent) and 255 (opaque ).* * This operation requires the operating system's advanced*

Mainly shell several common operations: 1 shell and awk combined with 2 shell string operations 3 shell file operations and awk combined 4 file MD5 verification 5 results output 6 passing parameters, etc.     The following content cannot be

1. system environment variables after the user logs on to the system:$ Home user's own directory$ Path: the directory to be searched during Command Execution$ TZ Time Zone$ Mailcheck the number of seconds to check whether a new letter exists$ PS1

Notes for shell script programs: variables can be directly used without prior declaration; the variable does not have any data type. The default value is a string; no space is allowed on any side of the equal sign of the value assignment operation.