Px_ipc_name()函数

/* include px_ipc_name */#include        "unpipc.h"char *px_ipc_name(const char *name){        char    *dir, *dst, *slash;        //分配的空间在哪里释放的哦！@deprecated         if ( (dst = malloc(PATH_MAX)) == NULL)                return(NULL);                /* 4can override default directory with environment variable */        if ( (dir = getenv("PX_IPC_NAME")) == NULL) {#ifdef  POSIX_IPC_PREFIX                dir = POSIX_IPC_PREFIX;         /* from "config.h" */#else                dir = "/tmp";                           /* default */#endif        }                /* 4dir must end in a slash */        slash = (dir[strlen(dir) - 1] == '/') ? "" : "/";        snprintf(dst, PATH_MAX, "%s%s%s", dir, slash, name);        return(dst);                    /* caller can free() this pointer */}/* end px_ipc_name */char *Px_ipc_name(const char *name){        char    *ptr;        // gcc -posix -E -dM - </dev/null >#ifdef linux        ptr = (char *)name;#else        if ( (ptr = px_ipc_name(name)) == NULL)                err_sys("px_ipc_name error for %s", name);#endif        return(ptr);}