execute perl one-liner over ssh (problem with quotes)
I'm trying to execute some perl code remotely and I can't seem to figure out what to do with all the quotes. Here is an example:
# ssh root@10.0.0.1 " perl -e '$var=\"a\"; print $var;' "
syntax error at -e line 1, near "="
Execution of -e aborted due to compilation errors.
# ssh root@10.0.0.1 " perl -e '$var="a"; print $var;' "
(nothing happened. It just returned)
# ssh root@10.0.0.1 " perl -e 'print \"a\";' "
a (it works without the variable. why?)
# ssh root@10.0.0.1 "./test_script"
a (it works if I place the perl code in a file first and then execute)
[root@10.0.0.1]# perl -e '$var="a"; print $var;'
a (it works if I execute the code directly on the machine.)
So the code works if I execute on the machine directly or place it in a file first, but the quotes seem to mess up when trying to execute it inside the ssh command. Any ideas?
# ssh root@10.0.0.1 " perl -e '$var=\"a\"; print $var;' "
syntax error at -e line 1, near "="
Execution of -e aborted due to compilation errors.
# ssh root@10.0.0.1 " perl -e '$var="a"; print $var;' "
(nothing happened. It just returned)
# ssh root@10.0.0.1 " perl -e 'print \"a\";' "
a (it works without the variable. why?)
# ssh root@10.0.0.1 "./test_script"
a (it works if I place the perl code in a file first and then execute)
[root@10.0.0.1]# perl -e '$var="a"; print $var;'
a (it works if I execute the code directly on the machine.)
So the code works if I execute on the machine directly or place it in a file first, but the quotes seem to mess up when trying to execute it inside the ssh command. Any ideas?
Enclose the command in single quotes, not double quotes
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to see what is happening
echo " perl -e '$var=\"a\"; print $var;' "
echo " perl -e '$var="a"; print $var;' "
echo "perl -e '"'$var="a";print $var'"'"
echo " perl -e 'print \"a\";' "
echo " perl -e '$var=\"a\"; print $var;' "
echo " perl -e '$var="a"; print $var;' "
echo "perl -e '"'$var="a";print $var'"'"
echo " perl -e 'print \"a\";' "
ASKER
Good job!
ssh root@10.0.0.1 "perl -e '"'$var="a";print $var'"'"
does work, but I'm not sure why. I see the only thing you changed was to surround the perl command with '"' (singel-double-single quote) instead of ' (single quote). Can you explain why you did that?
ssh root@10.0.0.1 "perl -e '"'$var="a";print $var'"'"
does work, but I'm not sure why. I see the only thing you changed was to surround the perl command with '"' (singel-double-single quote) instead of ' (single quote). Can you explain why you did that?
I put the $ and the " in ''
and put the ' in ""
and put the ' in ""
ASKER
Your method does work, but I still understand the why it works. Can you explain?
"perl -e '" quotes the '
'$var="a";print $var' quotes the $ and the "
"'" quotes the '
This is more of a shell question than a Perl question
'$var="a";print $var' quotes the $ and the "
"'" quotes the '
This is more of a shell question than a Perl question
ASKER
Thanks