发布时间：2013-04-23 18:52:38

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发布时间：2013-04-18 20:22:04

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发布时间：2013-04-15 23:26:39

1. The exit command terminates a script. It can also return a value, which is available to the script's parent process.2. $? reads the exit status of the last command executed. After a function returns, $? gives the exit status of the last command executed in the function. Following the execution o.........【阅读全文】

发布时间：2013-04-10 14:49:12

转自：http://blog.csdn.net/coder_jack/article/details/6278959ubuntu用久了以后发现由于内核不断的更新导致grub启动列表的内容越来越多，看着不顺眼，其次，每个内核在硬盘上都要占据100M左右的空间，想着都不爽，我看还是删掉一些把，反正我只能用一个内核，其他的也没有存在价值。那就用如下的命令去删除不要的内.........【阅读全文】

发布时间：2013-04-09 00:23:51

1. Note that $variable is actually a simplified form of ${variable}.2. An uninitialized variable has no value, however it acts as if it were 0 in an arithmetic operation. This is undocumented (and probably non-portable) behavior, and should not be used in a script.(P31)3. 此处a的值为21，使用let对.........【阅读全文】