Redirection for the make use of Linux

In Linux, the scripting language environment, that is, you use make xxx that other common Linux commands, such as Ls,find, and so on, different numbers, representing different meanings:

Digital	Meaning	Standard term
0	Standard input	stdin = Standard input
1	Standard output	stdout = standard output
2	Standard error Output	stderr = Standard Error

and the system default Stdin,stdout,stderr, is the screen, so, when you execute commands, such as make, after the output of the information can be seen on the screen.

Therefore, want to output the corresponding information to a file, the corresponding number with the redirect symbol ' > ', the implementation of this information, redirected to the corresponding file, you can.

(The above two sentences, but also before too many people to explain, but did not indicate the white place.) ）

The following example shows the Make command, how to output the corresponding information to the corresponding file:

1. The most common way to export all the information from make output to a file is:
Make xxx > Build_output.txt
At this point, the default is not to change the output mode of the 2=stderr, or the screen, so if there is an error message, you can see on the screen.
2. Simply output the error (and warning) information in the make output to the file, ING, you can use:
Make xxx 2> build_output.txt
Accordingly, since the 1=stdout is not changed, or the screen, so, those command execution time output of normal information, or will be output to the screen, you can still see on the screen.
3. Simply output the normal (non-error, non-warning) information in the make output to a file that can be used:
Make xxx 1> build_output.txt
Correspondingly, because the 2=stderr is not changed, or the screen, so, those command execution time output error message, or will be output to the screen, you can still see on the screen.
4. To export normal output information and error messages to separate files, you can use:
Make xxx 1> build_output_normal.txt 2>build_output_error.txt
That is, the combined use of 1 and 2, normal information and error messages, are exported to the corresponding file.
5. All the information is exported to the same file:
Make xxx > Build_output_all.txt 2>&1
The 2>&1 indicates that the error message is output to &1, and &1 refers to the previous file: Build_output_all.txt.
Note: All of the above numbers, followed by the greater than the number ' > ', the middle can not have spaces.

Redirection for the make use of Linux