+
+#define alloca0(n) \
+ ({ \
+ char *_new_; \
+ size_t _len_ = n; \
+ _new_ = alloca(_len_); \
+ (void *) memset(_new_, 0, _len_); \
+ })
+
+#define strappenda(a, b) \
+ ({ \
+ const char *_a_ = (a), *_b_ = (b); \
+ char *_c_; \
+ size_t _x_, _y_; \
+ _x_ = strlen(_a_); \
+ _y_ = strlen(_b_); \
+ _c_ = alloca(_x_ + _y_ + 1); \
+ strcpy(stpcpy(_c_, _a_), _b_); \
+ _c_; \
+ })
+
+#define procfs_file_alloca(pid, field) \
+ ({ \
+ pid_t _pid_ = (pid); \
+ char *_r_; \
+ _r_ = alloca(sizeof("/proc/") -1 + DECIMAL_STR_MAX(pid_t) + 1 + sizeof(field)); \
+ sprintf(_r_, "/proc/%lu/" field, (unsigned long) _pid_); \
+ _r_; \
+ })