libpbm

NAME
SYNOPSIS
DESCRIPTION - PACKAGE-WIDE ROUTINES
DESCRIPTION - PBM-SPECIFIC ROUTINES
SEE ALSO
AUTHOR

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.

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 )

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 variables. 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 calling 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 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 pbm_writepbminit() and pbm_writepbmrow().

SEE ALSO

libpgm(3), libppm(3), libpnm(3)

AUTHOR

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