How to get the string with special char $ and '

Question

I have a basic question but not able to figure it out how to do this.

I need to frame a command string with a password from a C file and need to execute that command.I am using Linux.

what I am doing is

sprintf(command, "mycommand with password=$passw'ord");
system(command);

The issue what I am facing is when I am using ' during the command execution as follow '$passw\\'ord' ,it is not working.

when tried as follow

sprintf(command, "mycommand with password='$passw\\'ord'"); //not working it showing > in the terminal and showing error as unterminated '

but when passing only '$password' is working ,but I need to pass the ' character also.

To try we can use

echo  '$password' //working
echo  '$passw\\'ord' //Not working

Is there any thing for this.

Answer 1

Except the single-quote ( ' ) character, everything else can be included inside a single-quoted string and with no escapes. Bash makes no special interpretation of single-quoted strings and and just passes through the literal characters.

Remember that mixing single and double-quoted strings freely is supported. Thus

$ echo 'my command with password=$passw'"'"'ord'
my command with password=$passw'ord

works. In C this would translate into

char const *cmd = "'my command with password=$passw'\"'\"'ord'";