Shell Programming and Scripting

If I echo "\\" I get a backslash returned

Code:

~$ echo "\\"
\

Why doesn't this work:

Code:

string=`echo "\\"`
echo $string

I get the error message:

bash: command substitution: line 1: unexpected EOF while looking for matching `"'
bash: command substitution: line 2: syntax error: unexpected end of file

How do I eval a string like "awk 'BEGIN{ FS="\""}/string/ {print $0}' filename" and attach the result to a variable??

The backslash of this string creates a problem when i try

Code:

variable=`eval $string`

Code:

string=`echo "\\\"`
echo $string
\

Backslashes within backquoted command substitutions do not behave the same way they would outside of backqutoed command substitution even when the command is otherwise identical (in this case an echo with a double-quoted argument). The backslashes are seen/parsed/consumed by the shell before it even invokes the subshell. In this case, you are left with echo "\" and so you get the error that the closing quote is not found because it's being escaped in the subshell.

Do yourself a massive favor and abandon all use of this archaic and obsoleted form of command substitution. It's quirky and buggy. Use $(...) instead and you'll live longer.

The string=$(echo "\\") form will work as expected, even as the command within the parenthesis increases in complexity. The same cannot be said of `...`.

Regards,
Alister