Some of the shell's points of attention (gradually replenished)

1) If you want to search the file name beginning with AB,#find/-name "ab*", pay attention to double quotation marks, or you will get an error.

If you search a file, AB starts the sentence,#grep "^ab" file name , if using cat, is to show the full text.

2)#!!: Executes the last command entered

#!$: Executes the last executed variable, these two commands are not paged out with the UP arrow.

3) Ctrl + Z is dormant (although it hints that stop is actually paused), CTRL + C is completely down the task.

After Ctrl + Z, you can use the #jobs to see the task that has been dormant, if you want to restart the task that has been dormant, is #fg + serial number.

4) The TR command is a replacement command,#cat 1.txt|tr' A-Z ' A-Z, which means that all lowercase letters of 1.txt are converted to uppercase letters.

But this command is not very intelligent,#cat 1.txt|tr ' James ' Bond, such a command is not to separate the word James to bond, but instead of all J a m e s letters are converted to B o n d these four letters, but Bond less one, then use the end of D to fill up.

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This is the replacement of five letters corresponding to five letters.

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This is the replacement of five letters corresponding to four letters. In short, this TR command is not as good as a replacement after vim.

5)#export a=65535, this is to set the global variable A is 65535, if the use of #bash into the child shell, then a $ A is equal to 65535, this time can be set separately a=777, So in this layer of the child shell a=777, using #exit exit the child shell, a or is equal to 65535.

If you want to cancel the assignment of a variable,#unset variable .

This article is from "Life is waiting for Gordo" blog, please make sure to keep this source http://chenx1242.blog.51cto.com/10430133/1766126

Some of the shell's points of attention (gradually replenished)