Shell

From: http://aaronw.me/static/779.html This is the first method: (punctuation will be missed)#! /Bin/Shawk 'in in {hextab = "0123456789abcdef" for (I = 1; I This is the second method:#/Bin/Shawk 'in in {for (I = 0; I 1); printf "% s", substr (I, 1,

In the previous chapters, we have been able to remove encrypted data.ProgramThe original il bytecode. These bytecode are hexadecimal, and it is very difficult for my brain to read them directly. This chapter describes how to translate bytecode into

Enter bind-P to view all keyboard bindings. CTRL-related shortcut keysCTRL-A is equivalent to the Home Key, used to position the cursor to the beginning of the lineCTRL + B: move the cursor to the leftCTRL + C: Kill the current processCTRL + D:

Shell can be extended, shell ExtensionProgramThe following functions can be implemented. ◇ Specific file type, all file types, network neighbors, recycle bin, drive, network shared folder, printer, disc drive, directory, folder background (

If the notification area icon is usedProgramIt should be a graphical user interface program with a window,Like a common window program, you should create a main window and process window messages. I. RelatedAPI 1,Shell_policyicon Sends

1. Diff 1) Name Diff-find differences between two files Synopsis Diff [Options] From-file to-file Description In the simplest case, diff compares the contents of the two files from-file and to-file. 2) Option A single letter preceded

3. Route 1) route [-nee] ROute add [-net |-host] [domain or host] netmask [mask] [GW | Dev] Route del [-net |-host] [domain or host] netmask[Mask] [GW | Dev] 2) Option ①-N: not usedProtocolOr host name, directly using IP or port number; ②-

1,Which Which-shows the full path of (Shell) commands. Which [Option] 2,Whereis Whereis-locate the binary, source, and manual page files for a command Whereis [Option] filename 3,Find Find-search for files in a directory hierarchy Find [

1. Description /Sbin/ldconfig-configure dynamic linker Run-Time Bindings Ldconfig Option 2. Option 1)-P: indicates that ldconfig prints the names of all the shared libraries saved in the current cache file. 2)-V: ldconfig displays the

1. Description Strace-trace system CILS and Signals 2. Option 1) strace-p pid tracks a background process 2) strace-O filename outputs the trace result to the file 3) strace-T records the time spent on each system call. You can see which

1. Tail-output the last part of Files Tail [Option] [+/-num]... [file]... 2. Option ①-F,: Output appended data as the file grows; ②-S,: With-F, sleep for S seconds (default 1.0) between iterations. ③-N,: output the last n lines, instead of

1. About the prompt, special Variables 1) Bash has two levels of prompt. The first-level prompt is often seen when Bash is waiting for command input. The default value is the $ symbol, and PS1 is the variable value. The second-level prompt is

1. Expression writing: [2] Regex_ip = "(2 [0-4] [0-9] | 25 [0-5] | 1 [0-9] [0-9] | [1-9]? [0-9]) (\. (2 [0-4] [0-9] | 25 [0-5] | 1 [0-9] [0-9] | [1-9]? [0-9]) {3 }" It means (0-255) (point 0-255) 3 times Echo "123.1.1.1" | grep-e "$ regex_ip"

In the past, when grub information on the machine was lost or damaged, use rescue mode to enter and then reinstall grub-install/dev/SDA.For some reason, grub-install/dev/SDA may encounter more or less problems during execution. We can also use

   Interactive Shell and non-interactive shell Interactive ModeShell waits for your input and immediately executes the command you submitted. This mode is called interactive because shell interacts with users. This mode is also very familiar to

The chmod command is very important for changing the access permissions of files or directories. You can use it to control access to files or directories.This command can be used in two ways. One is the text setting method that contains letters and

Who All users currently logged in to the system Cat Examine the contents of a file WC-l WC-W WC-C Get a count of the total number of lines, words, and characters of information contained in a file  

In the process of using datastage to extract data, it is often required to extract data in Quasi Real Time (such as synchronizing data every 3 minutes. These requirements can be implemented using crontab + shell. As shown in, this is the entire

The simplest debugging command is the echo command. You can use echo to print any variable value in any suspected error. This is why most shell Programmers spend 80% of their time debugging programs. The benefit of a shell program is that it does

Directly run the Code: #!/bin/bashfunction usage{ echo "Usage: $0 " echo "e.g. $0 eth0 2" exit 1}if [ $# -lt 2 ];then usagefieth=$1interval=$2in_old=$(cat /proc/net/dev | grep -w $eth | sed -e "s/\(.*\)\:\(.*\)/\2/g" |