Return to stak.h CVS log

Up to [Research Unix] / researchv8dc / cmd / sh

Annotation of researchv8dc/cmd/sh/stak.h, revision 1.1

1.1     ! root        1: /*     @(#)stak.h      1.3     */
        !             2: /*
        !             3:  *     UNIX shell
        !             4:  *
        !             5:  *     Bell Telephone Laboratories
        !             6:  *
        !             7:  */
        !             8: 
        !             9: /* To use stack as temporary workspace across
        !            10:  * possible storage allocation (eg name lookup)
        !            11:  * a) get ptr from `relstak'
        !            12:  * b) can now use `pushstak'
        !            13:  * c) then reset with `setstak'
        !            14:  * d) `absstak' gives real address if needed
        !            15:  */
        !            16: #define                relstak()       (staktop-stakbot)
        !            17: #define                absstak(x)      (stakbot+Rcheat(x))
        !            18: #define                setstak(x)      (staktop=absstak(x))
        !            19: #define                pushstak(c)     (*staktop++=(c))
        !            20: #define                zerostak()      (*staktop=0)
        !            21: 
        !            22: /* Used to address an item left on the top of
        !            23:  * the stack (very temporary)
        !            24:  */
        !            25: #define                curstak()       (staktop)
        !            26: 
        !            27: /* `usestak' before `pushstak' then `fixstak'
        !            28:  * These routines are safe against heap
        !            29:  * being allocated.
        !            30:  */
        !            31: #define                usestak()       {locstak();}
        !            32: 
        !            33: /* for local use only since it hands
        !            34:  * out a real address for the stack top
        !            35:  */
        !            36: extern char            *locstak();
        !            37: 
        !            38: /* Will allocate the item being used and return its
        !            39:  * address (safe now).
        !            40:  */
        !            41: #define                fixstak()       endstak(staktop)
        !            42: 
        !            43: /* For use after `locstak' to hand back
        !            44:  * new stack top and then allocate item
        !            45:  */
        !            46: extern char            *endstak();
        !            47: 
        !            48: /* Copy a string onto the stack and
        !            49:  * allocate the space.
        !            50:  */
        !            51: extern char            *cpystak();
        !            52: 
        !            53: /* Allocate given ammount of stack space */
        !            54: extern char            *getstak();
        !            55: 
        !            56: /* A chain of ptrs of stack blocks that
        !            57:  * have become covered by heap allocation.
        !            58:  * `tdystak' will return them to the heap.
        !            59:  */
        !            60: extern struct blk      *stakbsy;
        !            61: 
        !            62: /* Base of the entire stack */
        !            63: extern char            *stakbas;
        !            64: 
        !            65: /* Top of entire stack */
        !            66: extern char            *brkend;
        !            67: 
        !            68: /* Base of current item */
        !            69: extern char            *stakbot;
        !            70: 
        !            71: /* Top of current item */
        !            72: extern char            *staktop;
        !            73: 
        !            74: /* Used with tdystak */
        !            75: extern char            *savstak();

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.