  Static and stationary cylindrically symmetric space-times in general
relativity are considered, supported by distributions of cosmic strings
stretched in the azimuthal ($\varphi$), longitudinal ($z$) or radial ($x$)
directions or and by pairs of mutually opposite radiation flows in any of these
directions. For such systems, exact solutions are obtained and briefly
discussed, except for radial strings (a stationary solution for them is not
found); it is shown that static solutions with $z$- and $\varphi$-directed
radiation flows do not exist, while for $z$-directed strings a solution is only
possible with negative energy density. Almost all solutions under discussion
contain singularities, and all stationary solutions have regions with closed
timelike curves, hence only their well-behaved regions admit application to
real physical situations.
