On Feb 6, 2008 6:44 PM, Jonathan Berry <berryja at gmail.com> wrote: > On Feb 6, 2008 5:42 PM, MHR <mhullrich at gmail.com> wrote: > > According to the man pages for sem_wait, etc., POSIX semaphores are > > available in Linux 2.6 (with the right NTPL threading in glibc). > > > > However, I have a program that compiles just fine but won't link because it > > can't find the library for the semaphore operations. > > > > What am I missing? > > > > I ran a find and grep through all the libc's on the system and they turned > > up nothing: > > > > $ find /lib /usr/lib -name "*libc\.*" -print -exec nm {} 2>/dev/null \; | > > grep sem_ > > > > (no results) > > > > Time is critical (yeah, I know...). > > >From man sem_overview: > "Linking > Programs using the POSIX semaphores API must be compiled with cc -lrt > to link against the real-time library, librt." > > Are you linking with -lrt? > Works. Thanks. Must have been working on it too long - I saw that and misread it. mhr