linux at command examples

The test command expects to find a parameter on the command line that is considered empty when the shell does not assign a value to the variable. This means that when the script is being processed, test will report the error once the script is looking for a parameter that does not exist. When you try to protect the script, you can solve the problem by including all the arguments in double quotes. The shell

/-atime 5028. Find all files that have been modified within 50-100 days# Find/-mtime +50–mtime-10029. Find all files changed within 1 hours# Find/-cmin-6030. Find all files modified within 1 hours# Find/-mmin-6031. Find all the files accessed within 1 hours# Find/-amin-6032. Find all files of length 50MB# Find/-size 50M33. Find all files of length in 50MB-100MB# Find/-size +50m-size-100m34. Find and delete all files larger than 100MB# Find/-size +100m-exec rm-rf {} \;35. Find all files that are

.... Perform echo "haha"0-23/2 * * * echo "haha"Attention:When the program is executed at the time you specify, the system will send you a letter showing what the program is doing, and if you do not wish to receive such a letter, please leave a blank in each lineAfter adding >/dev/null 2>1 can beExample 2:#每天早上6点10分6 * * * Date#每两个小时0 */2 * * * Date#晚上11点到早上8点之间每两个小时, 8 in the morning.0 23-7/2,8 * * * Date#每个月的4号和每个礼拜的礼拜一到礼拜三的早上11点0 4 * mon-wed date#1月份日早上4点0 4 1 Jan * DateExample$crontab-L lis

The WC is used for counting under Linux. Returns the number of rows, words, bytes, and so on in the file. For example: The code is as follows: WC Wc1.txt 3 5 Wc1.txt Output information in order: number of rows number of bytes file name. More specifically, a single statistic. Copy Code The code is as follows: #wc-M FileName: Number of characters displayed for a file #wc-L FileName: Displays the number of rows in a file #wc-L FileName: Display

more spaces followed by the grep line,. * Together, representing any character.650) this.width=650; "src=" http://s3.51cto.com/wyfs02/M02/57/95/wKiom1SelReQNIv_AAClEf8sRJs235.jpg "title=" 3.png " alt= "Wkiom1selreqniv_aaclef8srjs235.jpg"/>[] matches a specified range of characters such as: ' [gg]rep ' matches grep and grep.650) this.width=650; "src=" http://s3.51cto.com/wyfs02/M01/57/92/wKioL1Sel3iTSRT8AAA-1qieyZE214.jpg "title=" 4.png " alt= "Wkiol1sel3itsrt8aaa-1qieyze214.jpg"/>[^] matches a

Examples of sudo commands and sudo command examples Sudo: authorize normal users to execute a command and run it as a specified user. Configure sudu, enter the command mongodo, find the target line, and edit the configuration file under the target line. , The first co

=" mkdir set privilege " Width= "705" vspace= "5" style= "border:0px;"/>Print process information for creating a directoryIf we want to see the information, we can use the- v parameter to implement it. Examples are as follows: $ mkdir - v Ubuntu redhat Slackware 650) this.width=650; "src=" Http://www.linuxidc.com/upload/2014_03/140319121893607.png "alt=" mkdir verbose "width=" 705 "vspace=" 5 "style=" border:0px; "/>SummarizeThe Mkdir

replace spaces in all mp3 file names _ $ find . -type f -iname “*.mp3″ -exec rename “s/ /_/g” {} \;Example 15: execute two commands simultaneously in the find result On the find man page, the following is an example of the syntax for using two commands in a file search traversal. The following find command is used to traverse the file system once, list the files and directories with the setuid attribute, and write the/root/suid.txt file. if the file

Eight rm command examples that you may not know all about Deleting a file is similar to copying/moving a file. In Linux, there is a dedicated CommandrmTo complete all deletion-related operations. In this article, we will use some easy-to-understand examples to discuss the basic usage of this

Linux Command (1): ls command, linux Command ls The ls command is the most commonly used command in linux. The ls

12 ip command examples Year after year, we have been usingifconfigCommand to perform network-related tasks, such as checking and configuring Nic information. HoweverifconfigIt is no longer maintained and abolished in the latest version of Linux!ifconfigThe command has beenipCommand is replaced. ipCommand andifconfigTh

);}Example four: pointer and array relationships. Classic examples#include"stdio.h"intMain () {//Classic example Linux C program on page 85th inta[2][5]={1,3,5,7,9,2,4,6,8,Ten}; int(*p) [5],i;//Int (*p) [5] means p is a pointer to a one-dimensional pointer containing 5 elements, and P is the first address of a one-dimensional arrayp=A; for(i=0;i5; i++) printf ("%d",(*p) [i]); printf ("\ n"); P++;//p plu

Sed command details and examples The query function of the grep command, the stream editing function of the sed command, and the awk (which has now become a programming language) are more powerful text editing commands. in Linux system management, it plays an important and c

Linux Command: cd command learning and use, linux Command cd Learning The Linux cd command is the most basic command statement in

The top command in Linux displays the processes that are running on the system. It is one of the most important tools for system administrators. is widely used to monitor the load on the server. In this article, we will explore the details of the top command. The top command is an interactive

Seven examples of the uniq command: the uniq command in Linux can be used to process repeated lines in text files, this tutorial explains some of the most common usage of the uniq command, which may be helpful to you. The following File test will be used as the test file...

Tip:1. Use the shortcut key (Ctrl + F), enter the command you want to know, and press enter to quickly find the command;2. Some commands have not yet been updated. In the future, we will take the time to update them. Please pay attention to the Yunqi community network.Linux Commands1. File managementCatChattrChgrpChmodChownCksumCmpDiffDiffstatFileFindGitGitviewIndentCutLnLessLocateLsattrMattribMcMdelMdirMkt

of the person* ---------------------------------------------------------------* 20151218 V1.0 Zhou Zhaoxiong created***********************************************************************/void findstackdirection (void) {UINT8 istackaddr = 0; Used to get the stack addressstatic UINT8 *pstackaddr = NULL; Address for storing the first istackaddrif (pstackaddr = = NULL)//First entry { pstackaddr = iStackAddr; Save Istackaddr's addressfindstackdirection (); Recursive }

Seven examples of the uniq command: The uniq command in Linux can be used to process repeated lines in text files, this tutorial explains some of the most common usage of the uniq command, which may be helpful to you. The following file test will be used as a test file to ex