shell scripting basics

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The Until loop executes a series of commands until the condition is true. The Until loop and the while loop are just the opposite of the processing mode. The general while loop is better than the until loop, but at some point it is only rare that the until loop is more useful.The Until loop format is:Until Commanddo Statement (s) to being executed until command is TruedoneThe command is usually a conditional expression, and if the return value is false, the statement in the loop body continues

2 3 Do For var2 in 0 5 Do if [ $var 1 -eq 2-a $var 2 -eq 0 ] /c0> Then break 2 Else Echo "$var 1 $var 2" fi Done Done As above, break 2 means to jump out of the outer loop directly. Operation Result:1 01 5Continue commandThe continue command is similar to the break command, with only a little difference, and it does not jump out of all loops and just jumps out of the current loop.To modify the above example: #!/bin/bash While : Do echo- n "Input a num

] ~]# Expr 2 * 3expr:syntax errorSecond, let command[[email protected] ~]# let A=2+3[[email protected] ~]# echo $a 5[[email protected] ~]# let A=2-3[[email protected] ~]# Echo $a -1[[email protected] ~]# let A=2*3[[email protected] ~]# echo $a 6[[email protected] ~]# let A=2/3[[email protected] ~]# echo $a 0[[email protected] ~]# b=4[[email protected] ~]# c=2[[email protected] ~]# let a= $b/$c [[email protected] ~]# Echo $a 2When using let, it is generally necessary to assign them to a variable

Shell BASICS (10) including shell scripts and shell Basics Preface Write it here; the basics of shell are almost finished. I hope you have a basic understanding of

Often, when people refer to the "Shell scripting language", they are bash,ksh,sh or other similar Linux/unix scripting languages emerging in their minds. Scripting languages are another way to communicate with a computer. Users can move the mouse and click on a variety of objects, such as buttons, lists, marquee, and s

What is a shell script Shell scripting (English: Shell script), also known as shell Command Draft, programmatic script, is a computer program and text file, the contents of a series of shell commands, through the Unix

What is a shell script sample Let's look at an example: #!/bin/sh cd ~ mkdir shell_tut cd shell_tut for ((i=0; i Example explanation Line 1th: Specify the script interpreter, here is the interpreter with/bin/sh Line 2nd: Switch to the current user's home directory Line 3rd: Create a directory Shell_tut Line 4th: Switch to the Shell_tut directory Line 5th: Cycle conditions, 10 cycles

Shell BASICS (II)-shell variables, basics-shell 1. Define Variables 1) when defining a variable, the variable name does not contain the dollar sign ($), for example:Var = "hello world"2) Note that there is no space between the variable name and equal sign, which may be diffe

Use PHP as the Shell scripting language, read the use of PHP as the Shell scripting language, -- English original: DarrellBrogdon, published in http://www.phpbuilder.com/columns/darrell20000319.php3) many may have thought about using PHP to write some program such as timed sending, but it is impossible to execute Darre

Use PHP as the Shell scripting language. We all know that PHP is a very good dynamic web page development language (fast speed, short development cycle ......). However, only a few people realize that PHP can also be well written. we all know that PHP is a very good dynamic web page development language (fast speed, short development cycle ......). However, only a few people realize that PHP can also be a g

As we all know, PHP is a very good dynamic web development language (fast, short development cycle ...). ）。 But only a very small number of people realize that PHP can also be very good as the language of writing shell scripts, when PHP as the language of writing shell scripts, he is not as powerful as Perl or bash, but he has a good advantage, Especially for those of me who are familiar with PHP but are no

How to use PHP as the Shell scripting language Probably a lot of people have thought of using PHP to write some timing letters and other programs, but there is no way to execute PHP on a regular basis;As we all know, PHP is a very good dynamic web development language (fast, short development cycle ...). ）。 But only a very small number of people realize that PHP can also be very good as the language of wr

How to use PHP as the Shell scripting language Probably a lot of people have thought of using PHP to write some timing letters and other programs, but there is no way to execute PHP on a regular basis;As we all know, PHP is a very good dynamic web development language (fast, short development cycle ...). ）。 But only a very small number of people realize that PHP can also be very good as the language of wr

to customize their command aliases and private script functions3. non-interactive shellThis is the shell used by the system to execute shell scripts.There is no command line prompt.Bash shell provides bash_env environment variables. When a non-interactive shell is started, bash_env is checked to see the startup file t

How to use PHP as a Shell scripting language. We all know that PHP is a very good dynamic web page development language (fast speed, short development cycle ......). However, only a few people realize that PHP can also be well written as S. We all know that PHP is a very good dynamic web page development language (fast speed, short development cycle ......). However, only a few people realize that PHP can a

As we all know, PHP is a very good dynamic web development language (fast, short development cycle ...). ）。 But only a very small number of people realize that PHP can also be very good as the language of writing shell scripts, when PHP as the language of writing shell scripts, he is not as powerful as Perl or bash, but he has a good advantage, Especially for those of me who are familiar with PHP but are no

We all know that PHP is a very good dynamic web page development language (fast speed, short development cycle ......). However, only a few people realize that PHP can also be a good language for writing shell scripts. When PHP is used as a language for writing shell scripts, it is not as powerful as Perl or bash, but he has a good advantage, especially for people who are familiar with PHP but are not famil

As we all know, PHP is a very good dynamic web development language (fast, short development cycle ...). ）。 But only a few people realize that PHP can also be a good language for writing shell scripts, and when PHP is the language that writes the shell script, he's not as powerful as Perl or bash, but he has a good advantage. Especially for people like me who are familiar with PHP but don't know much about