libpbm(3)libpbm(3)NAMElibpbm - 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 min-
chars 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 check-
ing.
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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 PBM_WHITE or
PBM_BLACK.
#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 pbm_allocarray() containing
the given number of rows.
void pbm_freerow( bit* bitrow )
Free a row of bits.
READING FILES
void pbm_readpbminit( FILE* fp, int* colsP, int* rowsP, int* formatP )
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libpbm(3)libpbm(3)
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 pbm_readpbminit().
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 vari-
ables. This function combines pbm_readpbminit(),
pbm_allocarray() and pbm_readpbmrow().
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 call-
ing routine has to free the allocated buffer with free().
pm_read_unknown_size() 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 force-
plain 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 pbm_writepbminit() and pbm_writepbm-
row().
SEE ALSOlibpgm(3), libppm(3), libpnm(3)AUTHOR
Copyright (C) 1989, 1991 by Tony Hansen and Jef Poskanzer.
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