The option is shown as "
-l_library_" (no space) or "
-l _library_" (with a space) and
c is the library argument,
-lc will link
-lfoobar would link
General information about options and arguments
UNIX commands often accept option arguments with or without whitespace. If you have an option
o which takes an argument
arg you can write
-o arg or
-oarg. On the other hand you can combine options that don't take an argument, e.g.
-a -b -c or
When you see
-lc you can only find out from the documentation (man page) if this is the combination of options
-c or option
-l with argument
c or a single option
See also https://www.gnu.org/software/libc/manual/html_node/Argument-Syntax.html
gcc is an exception from this general concept. You cannot combine options for