setenv(1) - phpMan

fesetenv (3)         - floating-point rounding and exception handling
fesetenv (3p)        - get and set current floating-point environment
setenv (3)           - change or add an environment variable
setenv (3p)          - add or change environment variable
unsetenv (3)         - change or add an environment variable
unsetenv (3p)        - remove an environment variable