问题
For the command: /usr/bin/sh -c "ls 1`" (a backquote after 1).
How to make it run successfully? Adding a backslash before "`" does not work. ` is a special char as we know, and I tried surrounding it with single quote too (/usr/bin/sh -c "ls 1'`'"), but that doesn't work either.
The error always are:
% /usr/bin/sh -c "ls 1\`"
Unmatched `
回答1:
You need to escape the backtick, but also escape the backslash:
$ touch 1\` $ /bin/sh -c "ls 1\\\`" 1`
The reason you have to escape it "twice" is because you're entering this command in an environment (such as a shell script) that interprets the double-quoted string once. It then gets interpreted again by the subshell.
You could also avoid the double-quotes, and thus avoid the first interpretation:
$ /bin/sh -c 'ls 1\`' 1`
Another way is to store the filename in a variable, and use that value:
$ export F='1`' $ printenv F 1` $ /bin/sh -c 'ls $F' # note that /bin/sh interprets $F, not my current shell 1`
And finally, what you tried will work on some shells (I'm using bash, as for the above examples), just apparently not with your shell:
$ /bin/sh -c "ls 1'\`'" 1` $ csh # enter csh, the next line is executed in that environment % /bin/sh -c "ls 1'\`'" Unmatched `.
I strongly suggest you avoid such filenames in the first place.
回答2:
Use single quotes instead:
/usr/bin/sh -c 'ls 1\`'
回答3:
/usr/bin/sh -c "ls '1\`'"
来源：https://stackoverflow.com/questions/1824160/escape-backquote-in-a-double-quoted-string-in-shell