Incrementing a variable: In this example, I haveused a while loopwhich will iterate will the value of theithe variable is less or equal to 5: i=1 while [ $i -lt 5 ] do echo i: $i let "i+=1" done And here's the output: Decrementing a variable: In the example of decrement,...
/bin/bashn=9999for(( i =1; i<=100;i++))do/root/testProgram$nsleep5 n=$((n+1))done REFER:How to increment a variable in bash?
# Assigning a variable using printf. $ printf -v date '%(%a %d %b - %l:%M %p)T\n' '-1' $ printf '%s\n' "$date" Fri 15 Jun - 10:00 AM 获取当前用户的用户名 CAVEAT:需要bash4.4+ $ : \\u # Expand the parameter as if it were a prompt string. $ printf '%s\n' "${_...
Setvariable valuesandattributes. Obsolete.See`help declare'. [root@-shiyan prog]# type -a fdisk for cd fdisk is /sbin/fdisk for is a shell keyword cd is a shell builtin [root@-shiyan prog]# type -t fdisk for cd ls __udisks file keyword builtin alias function [root@-shiyan prog]#...
Set variable values and attributes. Obsolete. See `help declare'.[root@250-shiyan prog]# type -a fdiskforcd fdisk is/sbin/fdiskforis a shell keyword cd is a shell builtin [root@250-shiyan prog]# type -t fdiskforcd ls __udisksfilekeyword ...
function increment() { #定义函数increment。 local sum #定义本地变量sum。 let "sum=$1+1" return $sum #返回值是sum的值。 } echo -n "The num is " increment 5 #increment函数调用。 echo $? #输出increment函数的返回值。 CTRL+D
This is an alternative to sed, awk, perl and other tools. The function below works by finding all leading and trailing white-space and removing it from the start and end of the string. The : built-in is used in place of a temporary variable....
By incrementing a variable each time the loop is executed, the commands can be run a specific number of times: n=1 while [ $n -le 10 ] do echo "$n" n=$(( $n + 1 )) done The true command can be used to create an infinite loop: ...
numberTwelve variable is equal to 12 你所看到的是if语句的第一行,它在检查变量的值是否真的等于12。如果是的话,语句就会停止,并发出numberTwelve is equal to 12的回显,然后在fi之后继续执行你的脚本。如果变量大于12的话,就会执行elif语句,并在fi之后继续执行。当你使用if或if/elif语句时,它是自上而下工作...
+= Plus-Equal (Increment a variable.) -= Minus-Equal (Decrement a variable.) *= Times-Equal (Multiply a variable.) /= Slash-Equal (Divide a variable.) %= Mod-Equal (Remainder of dividing a variable.)BitwiseOperatorsWhat does it do? << Bitwise Left Shift <<= Left-Shift-Equal >> ...