isinf(3)                                                       isinf(3)

  isinf()

  NAME

    isinf(), isinff() - test number for infinite value

  SYNOPSIS

    #include 

    int isinf (double x)
    int isinf (float x)

  DESCRIPTION

    The isinf(3) and isinff(3) functions test the argument x to see if it is
    effectively infinite. Both positive and negative infinities are tested.

  RETURN VALUES

    The isinf(3) and isinff(3) functions return 1 if the argument x is
    positive or negative infinity, and returns 0 otherwise.

  SEE ALSO

    isnan(3)

    math(3)

  USAGE NOTES

    All of these functions are thread safe.

    None of these functions are async-signal safe.