Learn the shell script every day.

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Primary stage:

--File operation:

--Document as a whole: increase, delete, copy, move;

--File content: Append, overwrite, empty;

--Regular expression:

--String:

--interception, splicing;

echo "ABCD" > ShellTest.log

: Writes "ABCD" to ShellTest.log, and if ShellTest.log does not exist, it will be created first ShellTest.log

echo "ABCD" >> ShellTest.log

: Append "ABCD" to ShellTest.log, if ShellTest.log does not exist, the ShellTest.log will be created first

echo "ABCD" | Tee ShellTest.log

: Writes "ABCD" to ShellTest.log and prints "ABCD" to standard output (Command line window), and if ShellTest.log does not exist, it will be created first ShellTest.log

echo "ABCD" | Tee-a ShellTest.log

: Append "ABCD" to ShellTest.log and "ABCD" to standard output (Command line window), if ShellTest.log does not exist, it will be created first ShellTest.log

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Learn the shell script every day.