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I'm getting this error
Syntax error: redirection unexpected
in the line:
if grep -q "^127.0.0." <<< "$RESULT" How I can run this in Ubuntu?
635
The standard output (STDOUT) or standard error (STDERR) of one command can be redirected as the standard input (STDIN) for another command using the “>” I/O redirection, and similarly, a standard input (STDIN) can be redirected as the standard output (STDOUT) for another command using the “<” I/O redirection.
Using “2>” re-directs the error output to a file named “error. txt” and nothing is displayed on STDOUT. 2. Here, 2>&1 means that STDERR redirects to the target of STDOUT.
In Linux, for redirecting output to a file, utilize the ”>” and ”>>” redirection operators or the top command. Redirection allows you to save or redirect the output of a command in another file on your system. You can use it to save the outputs and use them later for different purposes.
Input/Output (I/O) redirection in Linux refers to the ability of the Linux operating system that allows us to change the standard input ( stdin ) and standard output ( stdout ) when executing a command on the terminal. By default, the standard input device is your keyboard and the standard output device is your screen.
<<< is a bash-specific redirection operator (so it's not specific to Ubuntu). The documentation refers to it as a "Here String", a variant of the "Here Document".
3.6.7 Here Strings
A variant of here documents, the format is:
<<< word
The word is expanded and supplied to the command on its standard input.
A simple example:
$ cat <<< hello hello If you're getting an error, it's likely that you're executing the command using a shell other than bash. If you have #!/bin/sh at the top of your script, try changing it to #!/bin/bash.
If you try to use it with /bin/sh, it probably assumes the << refers to a "here document", and then sees an unexpected < after that, resulting in the "Syntax error: redirection unexpected" message that you're seeing.
zsh and ksh also support this syntax.
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if grep -q "^127.0.0." <<< "$RESULT" then echo IF-THEN fi is a Bash-specific thing. If you are using a different bourne-compatable shell, try:
if echo "$RESULT" | grep -q "^127.0.0." then echo IF-THEN fi If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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