error and set *ERRMSG and *ERR. */
long (*exec_child) (struct pex_obj *, int /* flags */,
const char */* executable */, char * const * /* argv */,
+ char * const * /* env */,
int /* in */, int /* out */, int /* errdes */,
const char **/* errmsg */, int */* err */);
/* Close a descriptor. Return 0 on success, -1 on error. */