snprintf/various.h

   1 #ifndef UST_SNPRINTF_VARIOUS_H
   2 #define UST_SNPRINTF_VARIOUS_H
   3
   4 #include <stdarg.h>
   5
   6 struct __sbuf {
   7         unsigned char *_base;
   8         int     _size;
   9 };
  10
  11 /*
  12  * stdio state variables.
  13  *
  14  * The following always hold:
  15  *
  16  *      if (_flags&(__SLBF|__SWR)) == (__SLBF|__SWR),
  17  *              _lbfsize is -_bf._size, else _lbfsize is 0
  18  *      if _flags&__SRD, _w is 0
  19  *      if _flags&__SWR, _r is 0
  20  *
  21  * This ensures that the getc and putc macros (or inline functions) never
  22  * try to write or read from a file that is in `read' or `write' mode.
  23  * (Moreover, they can, and do, automatically switch from read mode to
  24  * write mode, and back, on "r+" and "w+" files.)
  25  *
  26  * _lbfsize is used only to make the inline line-buffered output stream
  27  * code as compact as possible.
  28  *
  29  * _ub, _up, and _ur are used when ungetc() pushes back more characters
  30  * than fit in the current _bf, or when ungetc() pushes back a character
  31  * that does not match the previous one in _bf.  When this happens,
  32  * _ub._base becomes non-nil (i.e., a stream has ungetc() data iff
  33  * _ub._base!=NULL) and _up and _ur save the current values of _p and _r.
  34  */
  35 typedef struct __sFILE {
  36         unsigned char *_p;      /* current position in (some) buffer */
  37         int     _r;             /* read space left for getc() */
  38         int     _w;             /* write space left for putc() */
  39         short   _flags;         /* flags, below; this FILE is free if 0 */
  40         short   _file;          /* fileno, if Unix descriptor, else -1 */
  41         struct  __sbuf _bf;     /* the buffer (at least 1 byte, if !NULL) */
  42         int     _lbfsize;       /* 0 or -_bf._size, for inline putc */
  43
  44         /* operations */
  45         void    *_cookie;       /* cookie passed to io functions */
  46         int     (*_close)(void *);
  47         int     (*_read)(void *, char *, int);
  48         fpos_t  (*_seek)(void *, fpos_t, int);
  49         int     (*_write)(void *, const char *, int);
  50
  51         /* extension data, to avoid further ABI breakage */
  52         struct  __sbuf _ext;
  53         /* data for long sequences of ungetc() */
  54         unsigned char *_up;     /* saved _p when _p is doing ungetc data */
  55         int     _ur;            /* saved _r when _r is counting ungetc data */
  56
  57         /* tricks to meet minimum requirements even when malloc() fails */
  58         unsigned char _ubuf[3]; /* guarantee an ungetc() buffer */
  59         unsigned char _nbuf[1]; /* guarantee a getc() buffer */
  60
  61         /* separate buffer for fgetln() when line crosses buffer boundary */
  62         struct  __sbuf _lb;     /* buffer for fgetln() */
  63
  64         /* Unix stdio files get aligned to block boundaries on fseek() */
  65         int     _blksize;       /* stat.st_blksize (may be != _bf._size) */
  66         fpos_t  _offset;        /* current lseek offset */
  67 } LFILE;
  68
  69 #define __SLBF  0x0001          /* line buffered */
  70 #define __SNBF  0x0002          /* unbuffered */
  71 #define __SRD   0x0004          /* OK to read */
  72 #define __SWR   0x0008          /* OK to write */
  73         /* RD and WR are never simultaneously asserted */
  74 #define __SRW   0x0010          /* open for reading & writing */
  75 #define __SEOF  0x0020          /* found EOF */
  76 #define __SERR  0x0040          /* found error */
  77 #define __SMBF  0x0080          /* _buf is from malloc */
  78 #define __SAPP  0x0100          /* fdopen()ed in append mode */
  79 #define __SSTR  0x0200          /* this is an sprintf/snprintf string */
  80 #define __SOPT  0x0400          /* do fseek() optimisation */
  81 #define __SNPT  0x0800          /* do not do fseek() optimisation */
  82 #define __SOFF  0x1000          /* set iff _offset is in fact correct */
  83 #define __SMOD  0x2000          /* true => fgetln modified _p text */
  84 #define __SALC  0x4000          /* allocate string space dynamically */
  85
  86 #define __sferror(p)    (((p)->_flags & __SERR) != 0)
  87
  88 extern int ust_safe_fflush(LFILE *fp);
  89 extern int ust_safe_vfprintf(LFILE *fp, const char *fmt0, va_list ap);
  90
  91 #endif /* UST_SNPRINTF_VARIOUS_H */