The echo command doesn't want to interpret backlash escapes (with -e option attached). For example, I want it to ring a bell with:
echo -e \a
Nothing happens, except it prints:
a
or
\a
How to turn on interpreting or how to fix it?
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Jeff Schaller
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tuz.szymon
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A related question is https://unix.stackexchange.com/questions/65803/ . – JdeBP Feb 20 '18 at 19:32
2 Answers
7
In echo -e \a the \ in front of the a will be stripped off from the argument to echo by the shell before echo is called. It is exactly equivalent to
echo -e 'a'
For echo to receive \a as backslash-followed-by-a, the \ has to be passed as is to echo. This is done either through
echo -e '\a'
or
echo -e \\a
If this will actually produce an audible or visible bell may depend on other settings.
Kusalananda
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~/.inputrcis to configurereadline, it doesn't affect the terminal behaviour when you send a BEL character to it. – Stéphane Chazelas Feb 20 '18 at 19:50 -
@StéphaneChazelas Hmm... I wonder why I don't get any bells then. Is it because I run
tmux? But readline would at least control the shell's bells? – Kusalananda Feb 20 '18 at 20:29 -
1Yes, readline's
bell-stylewould control whether readline sends a\a(BEL) or a visual bell escape sequence or nothing to the terminal when it wants to notify the user. – Stéphane Chazelas Feb 20 '18 at 22:55 -
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You need to protect the \ from being interpreted by the shell. Try this:
echo -e '\a'
or
echo -e \\a
kartik_subbarao
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