read -p "Please Enter a Message:" message
开发者_运维技巧How can I add a line break after Message:
?
Just looking for the exact same thing. You can use:
# -r and -e options are unrelated to the answer.
read -rep $'Please Enter a Message:\n' message
And it will work exactly as asked:
Please enter a Message:
_
Here is an extract from the bash manpage explaining it:
Words of the form $'string' are treated specially. The word expands to string, with backslash-escaped characters replaced as specified by the ANSI C standard. Backslash escape sequences, if present, are decoded as follows:
- (...)
- \n new line
- (...)
The expanded result is single-quoted, as if the dollar sign had not been present.
Took me a while to find out.
Note that single quotes and double quotes behave differently in this regard:
A double-quoted string preceded by a dollar sign ($) will cause the string to be translated according to the current locale. If the cur- rent locale is C or POSIX, the dollar sign is ignored. If the string is translated and replaced, the replacement is double-quoted.
I like Huang F. Lei's answer, but if you don't like the literal line break, this works:
read -p "Please Enter a Message: `echo $'\n> '`" message
Shows:
Please Enter a Message: > _
...where _
is where the cursor ends up. Note that since trailing newlines are usually dropped during command substitution, I've included the >
afterward. But actually, your original question doesn't seem to want that prompt bit, so:
# Get a carriage return into `cr` -- there *has* to be a better way to do this
cr=`echo $'\n.'`
cr=${cr%.}
# Use it
read -p "Please Enter a Message: $cr" message
Shows
Please Enter a Message: _
There has to be a better way, though.
Here's an improvement on the accepted answer that doesn't require spawning a subshell:
read -p "Please Enter a Message:"$'\n' message
From the GNU Bash reference manual:
Words of the form
$'string'
are treated specially. The word expands to string, with backslash-escaped characters replaced as specified by the ANSI C standard.
$ read -p "Please Enter a Message:
> " message
Please Enter a Message:
Typing a "newline" between ':' and '"' directly.
Just to improve the answers of Huang F. Lei and of T.J. Crowder which I like (and added +1) .. You can use one of the following syntaxes too, which basically are the same, it depends on your taste (I prefer the first one):
read -p "$(echo -e 'Please Enter a Message: \n\b')" message
read -p "`echo -e 'Please Enter a Message: \n\b'`" message
which both will produce the following output:
Please Enter a Message:
_
where _ is the cursor.
In case you need a newline in any part of the string but the end, you can use \n
, for example
read -p "`echo -e '\nPlease Enter\na Message: '`" message
will produce
.
Please Enter
a Message: _
where . is a blank first new line and _ is the cursor.
Only to add a final trailing newline you have to use \n\b
as in my first example
From the bash
manpage:
-p prompt
Display prompt on standard error, without a trailing new-
line, before attempting to read any input. The prompt is
displayed only if input is coming from a terminal.
So, not with read
itself, and putting \n
in the message string just echoes \n
. The answer should be simple though - don't get read
to display the prompt:
echo "Please Enter a Message:" 1>&2
read message
read -p "$(printf 'Please Enter a Message:\n')" message
With printf
you can use \n
for line breaks.
read -p "Please Enter a Message:
Return" message
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