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NAME

       profil - execution time profile

SYNOPSIS

       #include <unistd.h>

       int  profil(unsigned short *buf, size_t bufsiz, size_t offset, unsigned
       int scale);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       profil(): _BSD_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500)

DESCRIPTION

       This routine provides a means to find out in what  areas  your  program
       spends  most  of  its time.  The argument buf points to bufsiz bytes of
       core.  Every virtual 10 milliseconds, the user’s program  counter  (PC)
       is examined: offset is subtracted and the result is multiplied by scale
       and divided by 65536.  If the resulting value is less than bufsiz, then
       the  corresponding  entry  in  buf  is  incremented.   If  buf is NULL,
       profiling is disabled.

RETURN VALUE

       Zero is always returned.

CONFORMING TO

       Similar to a call in SVr4 (but not POSIX.1-2001).

BUGS

       profil() cannot be  used  on  a  program  that  also  uses  ITIMER_PROF
       interval timers (see setitimer(2)).

       True  kernel  profiling  provides  more  accurate  results.   Libc  4.4
       contained a kernel patch providing a system call profil.

SEE ALSO

       gprof(1), setitimer(2), sigaction(2), signal(2)

COLOPHON

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