65

For example, $PATH and $HOME

When i type echo $PATH it returns my $PATH, but i want to echo the word $PATH and not what the actual variable stands for, echo "$PATH" doesn't work either.

  • yes use single quote like : echo '$PATH'. for more information about quoting, visit this and this – Pandya Oct 16 '14 at 12:24
  • @don only saw a dupe on serverfault. My bad. – geedoubleya Oct 16 '14 at 12:24
  • Possible duplicate of How to use a special character as a normal one? – Stéphane Chazelas Sep 14 '16 at 10:42
  • @StéphaneChazelas That question is almost two years newer than this one. – DisplayName Sep 14 '16 at 12:28
  • @DisplayName, yes but is intended as a "canonical" question to cover all those "how to I display special character X". (I'm not sure I like the idea of those "canonical" cover-it-all answers being used to close specific questions though which is why I just added it as a comment instead of a close vote). – Stéphane Chazelas Sep 14 '16 at 12:40
75

You just need to escape the dollar $.:

echo \$PATH
$PATH

Or surround it in single quotes:

echo '$PATH'
$PATH

This will ensure the word is not interpreted by the shell.

  • 1
    Thanks, it didn't say anything about echo -e on the man page. – DisplayName Oct 16 '14 at 11:35
  • The -e flag is used to expand, e.g, \t to a literal tab character. It is unrelated to escaping the dollar sign to prevent parameter expansion. – chepner Oct 16 '14 at 12:20
  • 2
    This doesn't work when directing to a file. echo '\$PATH' >> output.txt results in "/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/opt/vc/bin" being written to the file, not "$PATH". – Cerin Dec 17 '15 at 4:03
  • 2
    Very interesting, if you are using single quotes and an escaped character, then that should just echo \$PATH. What OS / package is your echo comand sourced from? – geedoubleya Dec 22 '15 at 15:55
  • @Cerin for you @stéphane answer worked echo '\044*' > first.txt it will output $* in first.txt – maq Jul 26 '18 at 17:31
20

$ in the syntax of most shells is a very special character. If we only look at Bourne-like shells it is used to introduce:

  1. parameter expansions as in $#, $var, ${foo:-bar}
  2. command substitution as in $(logname) (also ${ logname;} in some shells to avoid the subshell)
  3. arithmetic expansion as in $((1+1)) (also $[1+1] in some shells).
  4. other forms of quoting in some shells like $'\n' or $"localized string".

Except for the last case, those expansions/substitutions still occur inside double quotes (and inside $"..." in bash or ksh93)

To stop that $ from being treated specially, you need to quote it with either:

  • single quotes: echo '$PATH' or echo '$'PATH. The one you'd generally want to use as it escapes all characters (except itself) in most shells.
  • blackslash: echo \$PATH. Also inside double quotes: echo "\$PATH"
  • in some shells, some other quoting operator: echo $'$PATH', echo $'\44PATH' (assuming an ASCII compatible charset), echo $'\u0024'

Or make sure it's not part of a valid form of expansion as listed above:

  • echo "$"PATH
  • echo $""PATH, echo $"PATH". Those should be avoided because some shells like ksh93 and bash support the $"..." form of quotes.
  • echo $``PATH. No reason why you'd want to use that one except to show that it's possible.
  • echo "${$+$}PATH" and other convoluted ones...

Or you could output that $ another way:

  • with a Unix-compliant echo: echo '\044PATH' (some other echos need echo -e '\044PATH')
  • printf '\44PATH\n'
  • cat << \EOF
    $PATH
    EOF

Note how those backslashes need to be quoted as they also are special to the shell obviously.

Should hopefully be clear by now that although there are many ways to do it, there's no good reason you'd want to use anything else but echo '$PATH' here.

1

Note that literal $ inside double quotes can be a problem. It can be done by producing the $ outside the double quotes, like this:

echo "My terminal is $term, first file found in /dev is </dev/`ls /dev | head -n 1`>, the
dollar symbol is '"`echo '$'`"', and a newspaper costs "`echo '$'`"2.50."

or like this:

echo "$term is the value of "'$term'

OUTPUT:

My terminal is xterm, first file found in /dev is </dev/acpi>, the dollar symbol
is '$', and a newspaper costs $2.50.

xterm is the value of $term
  • Or echo "$term is the value of \$term" as already explained in another answer. Or printf '%s is the value of $term\n' "$term" as anyway one shouldn't use echo for arbitrary data. – Stéphane Chazelas Jan 9 '18 at 13:53
-2

Use:

echo ''\$PATH'' >> output.txt 

This will work.

  • 2
    please add a comment when down-voting – andreas-h May 17 '16 at 14:55
  • 2
    Or ec""h'''o''' ''""''\$P''A""TH'' – Stéphane Chazelas Sep 14 '16 at 10:00
  • I'm not sure what is being attempted by this answer. The answer is to use either \$ or single quotes. echo '$PATH' will print $PATH echo '\$PATH' will print \$PATH echo "\$PATH" will print $PATH echo ''\$PATH'' will technically do the right thing, but the two null strings serve no purpose. – bobpaul Apr 6 '17 at 16:42

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