Ls Command Syntax

The Linux shell refers to a program that allows users to manipulate computers by typing instructions to the keyboard. The shell executes http://www.aliyun.com/zixun/aggregation/18678.html > user-entered commands and displays the execution results on the monitor. The whole process of this interaction is text-based and differs from the graphical operations described in other chapters. This command-line-oriented user interface is called the CLI (command line ...).

1.2 Directory Operation command 1.2.1 View directory the command for viewing directory content is LS, which displays the contents of the current directory by default, and can be viewed by giving one or more directory names at the location of the command line arguments. The syntax format for the command is: LS [options] ... [filename] ... the LS command has multiple command-line options, such as:-A: Lists all files, including those with "." First file;-D: If you are following a directory, use this parameter to output only the name of the directory;-L: Displays file entries in long format, including ...

1.4 File permissions operation in a multi-user operating system, for security reasons, each file and directory need to be given access rights, and the permissions of each user are strictly defined. At the same time, users can give their own files the appropriate permissions to ensure that others can not modify and access. 1.4.1 Change File Master Linux assigns a file owner to each file, called the file Master, and the control of the file depends on the file master or Superuser (root). The creator of the file or directory has special rights to the files or directories created. All relationships in a file can be changed ...

8.2.1 Directory Operation command 8.2.1.1 view directory The command for viewing the contents of a directory is LS, which displays the contents of the current directory by default, and can be viewed by giving one or more directory names at the location of the command line arguments. The syntax format for the command is: LS [options] ... [filename] ... the LS command has multiple command-line options, such as the parameter feature description-a lists all files, including the "." First file-D if the following is a directory, then use this parameter to output only the name of the directory-L use the long format display ...

By completing this chapter, you will be able to do the following: Describes the effect of a return value in a conditional branch statement. Use the test command to parse the return value of a command. Use the IF and case structures in a shell program. &http://www.aliyun.com/zixun/aggregation/37954.html ">nbsp;1. Return value shell variable"? "To save the return value of the last executed command: 0: ...

Feature Description: Sets the color of the &http://www.aliyun.com/zixun/aggregation/37954.html ">nbsp;ls directive when displaying directories or files. Syntax: dircolors [color profile] or dircolors [-bcp][--help][--version] Supplemental Note: dircolors ...

The 7.for statement loops through each entry in the list, giving Var the next entry in the list each time the loop completes, until the end of the last entry is completed. Syntax: example: for VAR in list $ cat Test_fordo For X in 1 2 3 4 5 list A Dodone ...

Popen (PHP3, PHP4) popen---&http://www.aliyun.com/zixun/aggregation/37954.html ">nbsp; Open file Syntax: int popen (String command, String mode) Description: Returns a file metric that is the same as the index returned by fopen (), except that it can only be one-way.

Apache Pig, a high-level query language for large-scale data processing, works with Hadoop to achieve a multiplier effect when processing large amounts of data, up to N times less than it is to write large-scale data processing programs in languages ​​such as Java and C ++ The same effect of the code is also small N times. Apache Pig provides a higher level of abstraction for processing large datasets, implementing a set of shell scripts for the mapreduce algorithm (framework) that handle SQL-like data-processing scripting languages ​​in Pig ...