bash shopt

Set bash options with built-in set and SHOPT commandsThe set command can be used to customize the shell environment, using the option "O" to turn options on or off. For example, open the options: Set-o option, close the Select item: Set +O option.For example, to open the VI Interactive command-line edit, the following: [Email protected] ~]#Set-o#查看当前设置情况Allexport offBraceexpand onEmacs onErrexi

Problem: A log directory with a lot of 00, 01, 02 ... 31 's Date directory, how to list all directories between 00 and 12th numbers. That is, how to use the regular on top of the file name. Shopt (shell option so understand easy to remember) $ shopt autocd off cdable_vars off Cdspell off Checkhash off Checkjobs Off Checkwinsize on Cmdhist on compat31 out compat32 off COMPAT40 off compat41 Off

. How do I express all the hard drives?If you say sdx, SDXY?SDA[A-Z]? ---> Sdax can't match SDA SDB .Sda? --Sdab Sda2, and doesnot want to match the partition so sda2 cannot displayIf you want to do this, we can use extended wildcard characters .If you want to display more than one letter:Shopt-s Extglob; LS sd+ ([a-z])To find out that there are multiple letters behind the SD, so that the SD behind the number of those all drained .With Extglob, you can match more patterns.？ (): The value in par

The Bash Shell has a extglob option that allows the shell to identify 5 additional pattern matching operators, which makes it easier to match files.The Open method is simple, using the shopt command: Shopt-s extglobClose, use the shopt command: Shopt-u extglobAfter opening,

Shell built-in command Shopt this built-in command changes the optional behavior of the extra shell. Shoptshopt [-pqsu] [-o] [optname hellip;] switches the values of variables used to control various optional shell behaviors. If the option is not included or the-p option is used, the system displays the shell built-in command Shopt for all the options that can be set. This built-in command changes the opti

, you cannot reset this option to allow the Startup File to find whether the shell is restricted.If sourcepath is set, the source built-in command uses the value of path to find the directory containing the files provided as parameters. Enabled by defaultSynonym for source point (.)Shift_verbose if this option is set, when the moving count exceeds the number of positional parameters, the shift built-in command will print an error message The new option nocasematch has been introduced since versi

, the return value is 0, otherwise it is a non-zero value. When setting or canceling the option, the returned status is zero unless an optname is not a valid shell option. The shopt option list is as follows: if autocd is set, the name of a directory is executed as a parameter of the cd command. This option is only used in interactive shell. If cdable_vars is set, the built-in command cd is not a parameter of the directory name and is treated as a var

IntroductionThe shopt command allows you to set optional parameters for the shell.shopt [-PSU] [optname ...]-S turns on an option.-U turns off an option.-p lists all the options that can be set.Extglob OptionsIf the EXTGLOB option is turned on, the shell will enable pattern matching. Reference to Shell pattern matchingSee if the EXTGLOB option is on (default is OFF)$ shopt Extglobextglob offTurn on the EXTG

shopt commandThe shopt command is used to display and set the behavior options in the shell to enhance the shell's ease of use.Open and closeOpen shopt command: shopt-u extglobAfter opening, the following 5 pattern matching operators will be identified: ? (pattern-list)-The given pattern is matched 0 or 1 times;

Enabling the shell option with the shopt built-in command (EXTGLOB) recognizes several extended pattern matching operatorsThe pattern list is by | SegmentationView Shell Options ExtglobShopt |grep ExtglobStart Shell Option ExtglobShopt-s ExtglobTurn off shell option ExtglobShopt-u Extglob ? (pattern-list) Match a given pattern 0 or one time * (Pattern-list) Matches a given pattern 0 or more times

called. In addition, you can use multiple character options. To be recognized, these options must be placed before a single character option in the command line. -- Debugger Specify the configuration file for the debugger before starting the shell. Open the extended debugging mode (see the extdebug option of the shopt built-in command in shopt> ). -- Dump-po-strings A list of all double quotation mark

because VaR is not set or the value is null. (See the shell parameter expression Section)16. The redirection error caused by Shell built-in commands will not cause shell exit.17. When running in POSIX mode, a specific built-in command returns an error and does not cause shell to exit. (See POSIX Mode)18. Exec execution fails, and does not cause shell to exit. (See the built-in commands section of the Bourne shell)19. parsing errors will not cause shell exit.20. The simple spelling correction fu

values of the shell options and positional parameters.5. Position variablesCalling parameters passed to the script from the command line in the script$, $ ... : corresponding to the command line of the 1th, 2nd ... A parameter$: Command itself$*: All parameters passed to the script, all parameters as a whole[Email protected]: All parameters passed to the script, each parameter is independent$#: Number of arguments passed in a scriptShift [n]: Kicks out n parameters6. Logic operation:: With|| :

5.2 Bash Variables The following variables are set or used in Bash. Other shells generally do not process these variables. Some variables used by Bash are also described in other chapters: for example, for variables used by tools for controlling jobs, see 'job control variable '. BASH Execute the full path name of the

positioning parameters are a simple method to traverse switches and parameters, they do not always traverse the parameter list directly in this way. There is a built-in command shift, it can discard the parameter "$1" and forward the following parameters to one place. With the shift command, you can check every parameter, just as they are always the first parameter. List 9.2 shows a complete example of how to use Shift: Listing 9.2 param2.sh #! /Bin/b