libpbm(3)         Image Format Library C++ Reference Manual          libpbm(3)



NAME
     libpbm - functions to support portable bitmap programs

SYNOPSIS
     #include <pbm.h>
     cc ... libpbm.a


DESCRIPTION - PACKAGE-WIDE ROUTINES
   KEYWORD MATCHING
     int pm_keymatch( char* str, char* keyword, int minchars )

     Does a case-insensitive match of str against keyword.  str can be a
     leading sunstring of keyword, but at least minchars must be present.

   LOG BASE TWO
     int pm_maxvaltobits( int maxval )
     int pm_bitstomaxval( int bits )

     Convert between a maxval and the minimum number of bits required to hold
     it.

   MESSAGES AND ERRORS
     void pm_message( char* fmt, ... )

     printf() style routine to write an informational message.

     void pm_error( char* fmt, ... )

     printf() style routine to write an error message and abort.

     void pm_usage( char* usage )

     Write a usage message.  The string should indicate what arguments are to
     be provided to the program.

   GENERIC FILE MANAGEMENT
     FILE* pm_openr( char* name )

     Open the given file for reading, with appropriate error checking.  A
     filename of "-" is taken as equivalent to stdin.

     FILE* pm_openw( char* name )

     Open the given file for writing, with appropriate error checking.

     void pm_close( FILE* fp )

     Close the file descriptor, with appropriate error checking.






                                                                        Page 1

libpbm(3)         Image Format Library C++ Reference Manual          libpbm(3)



   ENDIAN I/O
     int pm_readbigshort( FILE* in, short* sP )
     int pm_writebigshort( FILE* out, short s )
     int pm_readbiglong( FILE* in, long* lP )
     int pm_writebiglong( FILE* out, long l )
     int pm_readlittleshort( FILE* in, short* sP )
     int pm_writelittleshort( FILE* out, short s )
     int pm_readlittlelong( FILE* in, long* lP )
     int pm_writelittlelong( FILE* out, long l )

     Routines to read and write short and long ints in either big- or little-
     endian byte order.

DESCRIPTION - PBM-SPECIFIC ROUTINES
   TYPES AND CONSTANTS
     typedef ... bit;
     #define PBM_WHITE ...
     #define PBM_BLACK ...

     each bit should contain only the values of PBMWHITE or PBMBLACK.

     #define PBM_FORMAT ...
     #define RPBM_FORMAT ...
     #define PBM_TYPE PBM_FORMAT
     #define PBM_FORMAT_TYPE(f) ...

     For distinguishing different file formats and types.

   INITIALIZATION
     void pbm_init( int* argcP, char* argv[] )

     All PBM programs must call this routine.

   MEMORY MANAGEMENT
     bit** pbm_allocarray( int cols, int rows )

     Allocate an array of bits.

     bit* pbm_allocrow( int cols )

     Allocate a row of the given number of bits.

     void pbm_freearray( bit** bits, int rows )

     Free the array allocated with pbmallocarray() containing the given
     number of rows.

     void pbm_freerow( bit* bitrow )

     Free a row of bits.





                                                                        Page 2

libpbm(3)         Image Format Library C++ Reference Manual          libpbm(3)



   READING FILES
     void pbm_readpbminit( FILE* fp, int* colsP, int* rowsP, int* formatP )

     Read the header from a PBM file, filling in the rows, cols and format
     variables.

     void pbm_readpbmrow( FILE* fp, bit* bitrow, int cols, int format )

     Read a row of bits into the bitrow array.  Format and cols were filled in
     by pbmreadpbminit().

     bit** pbm_readpbm( FILE* fp, int* colsP, int* rowsP )

     Read an entire bitmap file into memory, returning the allocated array and
     filling in the rows and cols variables.  This function combines
     pbmreadpbminit(), pbmallocarray() and pbmreadpbmrow().

     char* pm_read_unknown_size( FILE* fp, long* nread )

     Read an entire file or input stream of unknown size to a buffer.
     Allocate memory more memory as needed. The calling routine has to free
     the allocated buffer with free().  pmreadunknownsize() returns a
     pointer to the allocated buffer. The nread argument returns the number of
     bytes read.

   WRITING FILES
     void pbm_writepbminit( FILE* fp, int cols, int rows, int forceplain )

     Write the header for a portable bitmap file.  The forceplain flag forces
     a plain-format file to be written, as opposed to a raw-format one.

     void pbm_writepbmrow( FILE* fp, bit* bitrow, int cols, int forceplain )

     Write a row from a portable bitmap.

     void pbm_writepbm( FILE* fp, bit** bits, int cols, int rows, int forceplain )

     Write the header and all data for a portable bitmap.  This function
     combines pbmwritepbminit() and pbmwritepbmrow().

SEE ALSO
     libpgm(3), libppm(3), libpnm(3)

AUTHOR
     Copyright (C) 1989, 1991 by Tony Hansen and Jef Poskanzer.










                                                                        Page 3