Here Documents
This type of redirection instructs the shell to read input from
the current source until a line containing only delimiter (with no
trailing blanks) is seen. All of the lines read up to that point
are then used as the standard input for a command.
The format of here-documents is:
<<[-]word
here-document
delimiter
No parameter and variable expansion, command substitution,
arithmetic expansion, or pathname expansion is performed on word.
If any characters in word are quoted, the delimiter is the
result of quote removal on word, and the lines in the here-document
are not expanded. If word is unquoted, all lines of the
here-document are subjected to parameter expansion, command
substitution, and arithmetic expansion, the character sequence
\<newline>
is ignored, and \
must be used to quote the characters
\
, $
, and `.
If the redirection operator is <<-
, then all leading tab characters
are stripped from input lines and the line containing
delimiter. This allows here-documents within shell scripts to be
indented in a natural fashion.
<<- END_SCRIPT
语法(注意破折号符号)。 - Leon