Shell Programming--eof (reprint) that requires interaction

In shell programming, "EOF" is usually used in conjunction with "<<", "<<eof" means the input of subsequent inputs as subcommands or sub-shells until "EOF" is encountered,

Return to the keynote shell again, which can be interpreted as a delimiter (delimiter). Since it is a delimiter, the form is naturally not fixed, where "EOF" can be

Custom, but the front and back "EOF" must appear in pairs and cannot conflict with shell commands. It is used in the following form:

Interactive Program (command) <<eof

Command1

Command2

......

Eof

The content in the middle of "EOF" will be entered as standard input into the "interactive program", when the shell sees "<<" know the delimiter entered after it, when the shell sees

Delimiter, the middle portion of the two delimiter is used as the standard input.

Note: The first EOF must start with the redirect character <<, the second EOF must be shelf written, otherwise it will be an error; Of course, this iconic character doesn't work.

Reserved words, most commonly used or EOF.

Shell Programming--eof (reprint) that requires interaction