Which of the following characters can be combined with a separator string in order to read from the current input source until the separator string, which is on a separate line and without any trailing spaces, is reached?



A.

<<

B.

<|

C.

!<

D.

&<

題解

使用「<<」可以自定義結束輸入的字串。舉例來說:

cat << EOF > text.txt

緊接著輸入:

Line 1
Line 2
Line 3
EOF

當輸入「EOF」的時候,cat就會結束執行,並且把之前輸入的三行文字輸出到「text.txt」檔案中。

所以「text.txt」檔案的內容是:

Line 1
Line 2
Line 3