`echo -n`不打印任何内容

Question

I used this question to strip the newline from a string, but I've encountered a problem on one host.

For some reason, /bin/echo -n foo prints nothing on that host. I have no idea why that host behaves oddly. /bin/echo foo works fine. It's not the terminal, since echo -n foo > /tmp/bar also shows nothing.

/bin/echo --help says that is should work:

Usage: /bin/echo [OPTION]... [STRING]...
Echo the STRING(s) to standard output.

  -n             do not output the trailing newline
  -e             enable interpretation of backslash escapes
  -E             disable interpretation of backslash escapes (default)
      --help     display this help and exit
      --version  output version information and exit

% /bin/echo --version
echo (GNU coreutils) 5.97

What can possibly cause this not to work? Could there be some strange buffering in this bash-shell?

Answer 1

Based on information in comments, it appears that /bin/echo -n foo is producing the expected output, but it's being overwritten by your next shell prompt. (Most likely it's your shell, not your terminal settings.)

You can demonstrate this by running

/bin/echo -n foo | wc

which should produce this output:

  0       1       3

You can also try this:

/bin/echo -n foo ; sleep 5

This will delay your next shell prompt for 5 seconds, so you can see the output before it's overwritten.

(What shell are you using? What's the value of $PS1 ?)