linux - Print single quotes in shell script using option -c

You can't nest single quotes in bash, so the line is
interpreted as

/bin/bash -l -c 'echo
            "'John'"'
 |......| ---------- single quoted
 |....| ----- not
            quoted
 |.| ---
            quoted

So, properly escape the
single quotes:

/bin/bash -c 'echo
            "'\''John'\''"'

or, if the string
in single quotes is really simple,

/bin/bash
            -c 'echo "'\'John\''"'