declare -i n 和 arithmetic evaluation

dearvoid

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1^# dearvoid 发表于 2007-08-18 16:37

declare -i n 和 arithmetic evaluation

以前不知道, 今天刚看见的:

引用:

-(dearvoid@LinuxEden:Forum)-(~/tmp)-
[29908 0] ; declare -i n
-(dearvoid@LinuxEden:Forum)-(~/tmp)-
[29908 0] ; n=2
-(dearvoid@LinuxEden:Forum)-(~/tmp)-
[29908 0] ; echo $n
2
-(dearvoid@LinuxEden:Forum)-(~/tmp)-
[29908 0] ; n=2*n
-(dearvoid@LinuxEden:Forum)-(~/tmp)-
[29908 0] ; echo $n
4
-(dearvoid@LinuxEden:Forum)-(~/tmp)-
[29908 0] ; n=n^2
-(dearvoid@LinuxEden:Forum)-(~/tmp)-
[29908 0] ; echo $n
6
-(dearvoid@LinuxEden:Forum)-(~/tmp)-
[29908 0] ; n=n**2
-(dearvoid@LinuxEden:Forum)-(~/tmp)-
[29908 0] ; echo $n
36
-(dearvoid@LinuxEden:Forum)-(~/tmp)-
[29908 0] ; n='n - 4'
-(dearvoid@LinuxEden:Forum)-(~/tmp)-
[29908 0] ; echo $n
32
-(dearvoid@LinuxEden:Forum)-(~/tmp)-
[29908 0] ; n=n/4
-(dearvoid@LinuxEden:Forum)-(~/tmp)-
[29908 0] ; echo $n
8
-(dearvoid@LinuxEden:Forum)-(~/tmp)-
[29908 0] ; o

li-jiahuan

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2^# li-jiahuan 发表于 2007-08-18 17:01

倒是相当方便