bash history

.: function with the previous M-. can be used in XshellIii. Command history:The bash process saves commands that have been executed by the user in its session to make it easier for the user to repeatedly execute a command, and the command history consists of two aspects:1. Commands that have been executed by the user;2. The path of the command executed by the user layer;In

Bash: insufficient permissions and insufficient bash Permissions This problem occurs today when a file is opened on a terminal under ubuntu. Suddenly, the file is read-only, so you need to open its user permissions. The specific implementation is as follows: chmod 777/home/example/filename. In this way, all permissions of this file are opened and can be accessed as much as possible. The details of chmod are

Linux bash integrated instance bash Script Editor, linuxbash Note: This is a simple bash Script Editor, but it has been tested. The reason for writing this blog is to exercise loop control language, functions, location parameters, local variables, function parameter calls, and inter-function calls, there is also the parameters for Obtaining user options and optio

The operating environment of the Bash Shell:Configuration values are divided into the overall system configuration values and preferences of each person, only some files placed in different places! Path and command search orderWhen a command (such as LS) is released, which LS is it running? Run the command in a relative/absolute path, such as "/bin/ls" or "./ls"; Run by alias to find the command; Run by

 Today burst a bash rce loophole, powerful. Look at the analysis of foreigners, feel the need to write their own understanding of this loophole. First, the problem results from a command env. Prototype: env [OPTION] ... [Name=value] ... [COMMAND [ARGS] ...] That's what man says: Display, set, or remove environment variables,run a command in a modified environment. My understanding is that using the key=value of the ENV command will first change th

In fact, after editing the bash script, you can use the Bash-n-X two options for script checking, not necessarily to run the program when the need to modify the script.Bash not only has the meaning of running scripts.No news is good news.I'm going to modify the original script a little bit.The-n effect I can not demonstrate now, before it is possible to directly point out the syntax errorThis is the effect

Bash variable types and bash Variables Local variable: it acts on the Current shell and is invalid for other shell processes other than the current shell and the Current shell Sub-processes. Assign a value to a local variable name='value' Value can be a string or a variable. The referenced variable uses $ {name}, $ name, or ''. Note: single quotes are strongly referenced, while double quotes are weak refere

In the process of reading any questions, welcome to communicate togetherEmail:[email protected]qq:1494713801when executing a script full_build.sh, I was always prompted :-bash:./full_build.sh:/bin/bash^m:bad interpreter:no such file or directoryOr remind syntax error:unexpected end of FileOne of the reasons for the above error is that the script file is in DOS format, that is, the line end of each line is i

Advanced Bash script, classic usage and cases, advanced bashIn linux, Bash scripts are very basic knowledge. You may feel very high when you listen to the scripts. Just like starting from the beginning, you may feel that script writing is a great tool. Although complicated scripts are very easy to understand, when we master the usage and skills of these scripts and practice more, we will always become a han

Description : This is a relatively simple bash script editor, but has been tested. The reason for writing this blog is to practice the loop control language, functions, positional parameters, local variables, and function parameter calls, as well as calls between functions, as well as parameters for obtaining user options and options.Note: The script options and the script options parameter get method use getopt and make further judgments, consult the

Bash script exercises and bash scripts Exercise 1: 1. Add five users, user1,..., user5; 2. The password of each user is the same as the user name. After the password is added, the command execution result is not displayed; 3. After each user is added, it must be displayed that the user has been added successfully. Useradd user1 Echo "user1" | passwd -- stdin user1 >/dev/null Echo "User1 added ." C

Bash metacharacters (upper) and bash characters Metacharacters Function Example Carriage return line feed End a command Space Split elements in a command line Ls/etc Tab Command auto-completion # Start a line of comment # This is a comment line " Multiple characters referenced but allowed to be replaced "$ File". ba

Bash internal variable, Bash variable Bash internal variables Some internal commands are invisible in the directory list. They are provided by the Shell itself. Common internal Commands include echo, eval, execexport, readonly, read, shift, wait, exit and point (.) Echo variable table Display the specified variable in the variable table to the standard output. Ev

Bash remote code execution vulnerabilities are really much more powerful than heart drops, but the impact is not very broad, but yesterday's analysis of the article bash The Remote Code execution vulnerability analysis at the end of this paper mentions the bulk problem of the vulnerability. One of the easiest ways to do this is to use the search engine's hacking technology, where I use the Google hacking sy

If you often use Linux command lines, using the history (history) command can effectively improve your efficiency. This article describes the 15 use cases of the history Command. Use HISTTIMEFORMAT to display the timestamp when you execute the history command from the command line... If you often use Linux command lin

Bash script skills-trap Command, bash script-trap Share a shell script technique. When you write a shell script, you generally only ensure that the function is available, but the program is not very robust and not robust enough. Most of them are script processing. The built-in trap command can handle unexpected system signals, for example: Trap "rm-f/var/lock/subsys/my_program_lock_file; Exit 0 "1 2 9 15

Wildcard characters in Bash (wildcard)*: Any character of any length.?: any single character []: Match range [^]: Exclude Match range [: alnum:] [: Alpha:] [: Blank:] [: cntrl:][:d Igit:] [: Graph:] [: Lower:] [:p rint:][ :p UNCT:] [: Space:] [: Upper:] [: xdigit:]Regular expressions.: Indicates matching any single character. *: Indicates that matches the preceding character any time, including 0 times. *: represents any character that matches any len

Learning bash notes-debugging shell programs and learning bash shell In shell, the simplest debugging assistant outputs the echo statement. Many echo statements can be put into the code for debugging, but it takes enough time to locate The information to view. You may need to output a lot to find the information you want to search.1. the most basic set-o Command Options are set-o Command Options. These opti

Location parameters$0, $1, $2, etc. .. (note that when the number of parameters is greater than 9, you should reference $ {10}, ${11 }...)Location parameter, which is passed to the script from the command line, to the function, or to a variable.Example: #! /Bin/bash #./Test. Sh first second third Output: First parameter first $0 =./test. Sh When the number of parameters is greater than 9: #! /Bin/bash #./

Guide If you use the Linux command line frequently, then using the history command can effectively improve your efficiency, this article will introduce you to the 15 uses of the historical command in the form of an instance. displaying timestamps using HisttimeformatWhen you execute the history command from the command line, you will usually only show the ordinal of the executed command and