Not able to unserstand the difference

[Joe Harry]

Guys,

I'm not able to interpret the following shell command...

#!/bin/bash
echo -n '$USER=' # -n option stops echo from breaking the line
echo "$USER"
echo "\$USER=$USER"  # this does the same thing as the first two lines

How does "\$USER=$USER" the same as given in line 2?

[Aurelian Tutuianu]

Well the following things you should know about bash:
- ' is different than ", the first specify a string which is not interpreted
- $ specify an environment variable, if is in 'string' is not interpreted, if is in "string" it is
- \$ is an escape sequence, so, even is present "string", the \$ is interpreted as a string, not as a value of a variable

Hope it helps