Shell programming continue break function return

Jump out of loops and function return values

one, exit cycle

In shell programming, there are usually two ways to exit a loop:

Contine: Is the end of the execution of the loop, the default is Contine 1, when contine 3 o'clock, then the 3rd layer of the loop;

Break: is to jump out of this loop, the default is break 1, when break 2 o'clock, it means to exit the second layer of the loop, into the 3rd layer loop;

So in the loop: contine n = Break n-1

[[email protected] ~/test] #vim for.sh #!/bin/bash For i in {1..3};d o For j in {101..103};d o For k in {1001..1003};d o If [$K-eq 1002];than #当执行玩第一轮i =1,j=101,k=1001, Output 1001, enter i=1,j=101,k=10 Contine 3 02 O'Clock Exit back, i=2,k=101,k=1001, Output 1001, enter i=2,k=101,k= Fi 1002 When exiting back, i=3, in turn, is displayed. Echo $K Done Done Done [[email protected] ~/test] #bash for.sh 1001 1001 1001 —————————————————————————————————————————————————— [[email protected] ~/test] #vim for.sh #!/bin/bash For i in {1..3};d o For j in {101..103};d o For k in {1001..1003};d o If [$K-eq 1002];than #当执行玩第一轮i =1,j=101,k=1001, Output 1001, enter i=1,j=101,k=10 Break 2 02 O'Clock Exit back, i=2,k=101,k=1001, Output 1001, enter i=2,k=101,k= Fi 1002 When exiting back, i=3, in turn, is displayed. Echo $K Done Done Done [[email protected] ~/test] #bash for.sh 1001 1001 1001

Second, function return value

When the function encounters a return for the first time, it jumps out of the function, similar to the contine in the For loop;

[[email protected] ~/test] #vim return.sh #!/bin/bash Ping () { echo "Ping 127.0.0.1" PING-C1-W1 127.0.0.1 &>/dev/null && return echo " Exited no " echo "Ping 127.0.0.2" PING-C1-W1 127.0.0.2 &>/dev/null && return 20 echo "Ping 127.0.0.3" PING-C1-W1 127.0.0.3 &>/dev/null &&return 30 } Ping [[email protected] ~/test] #bash return.sh Ping 127.0.0.1 [[email protected] ~/test] #echo $? 10

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Shell programming continue break function return