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Algorithms for Image Processing and Computer Vision Source Code

@c ----------------------------------------------------------------------
@node _filbuf, stdio
@heading @code{_filbuf}

@subheading Description

This is an internal function used to implement stream buffering.

@c ----------------------------------------------------------------------
@node fileno, stdio
@heading @code{fileno}
@subheading Syntax

@example
#include <stdio.h>

int fileno(FILE *file);
@end example

@subheading Description

This function returns the raw file descriptor number that @var{file}
uses for I/O. 

@subheading Return Value

The file descriptor number.

@c ----------------------------------------------------------------------
@node _findenv, environment
@heading @code{_findenv}

@subheading Description

This is an internal function used by @code{getenv} and @code{setenv}. 
@xref{getenv} @xref{setenv}

@c ----------------------------------------------------------------------
@node findfirst, file system
@heading @code{findfirst}
@subheading Syntax

@example
#include <dir.h>

int findfirst(const char *pathname, struct ffblk *ffblk, int attrib);
@end example

@subheading Description

This function and the related @code{findnext} are used to scan
directories for the list of files therein.  The @var{pathname} is a
wildcard that specifies the directory and files to search for (such as
@code{subdir/*.c}), @var{ffblk} is a structure to hold the results and
state of the search, and @var{attrib} is a combination of the following:

@table @code

@item FA_RDONLY

Include read-only files in the search

@item FA_HIDDEN

Include hidden files in the search

@item FA_SYSTEM

Include system files in the search

@item FA_LABEL

Include the volume label in the search

@item FA_DIREC

Include subdirectories in the search

@item FA_ARCH

Include modified files in the search

@end table

Any file that doesn't have any flag bits that aren't specified is
selected for the search.  Thus, if you specified @code{FA_DIREC} and
@code{FA_LABEL}, you would get all subdirectories, the volume label, and
any file that is neither read-only or modified. 

The results of the search are stored in @var{ffblk}:

@example
struct ffblk @{
  char ff_reserved[21];  /* used to hold the state of the search */
  char ff_attrib;        /* actual attributes of the file found */
  short ff_ftime;        /* hours:5, minutes:6, (seconds/2):5 */
  short ff_fdate;        /* (year-1980):7, month:4, day:5 */
  short ff_filler;       /* gcc aligns "long" different than DOS */
  long ff_fsize;         /* size of file */
  char ff_name[16];      /* name of file as ASCIIZ string */
@}
@end example

@subheading Return Value

Zero if a match is found, nonzero if none found.

@subheading Example

@example
struct ffblk f;
int done = findfirst("*.exe", &f, FA_ARCH|FA_RDONLY);
while (!done)
@{
  printf("%10u %2d:%02d:%02d %2d/%02d/%4d %s\n",
    f.ff_fsize,
    (f.ff_ftime >> 11) & 0x1f,
    (f.ff_ftime >>  5) & 0x3f,
    (f.ff_ftime & 0x1f) * 2,
    (f.ff_fdate >>  5) & 0x0f,
    (f.ff_fdate & 0x1f),
    ((f.ff_fdate >> 9) & 0x7f) + 1980,
    f.ff_name);
  done = findnext(&f);
@}
@end example

@c ----------------------------------------------------------------------
@node _findiop, stdio
@heading @code{_findiop}

@subheading Description

This is an internal function used by @code{fopen}. @xref{fopen}

@c ----------------------------------------------------------------------
@node findnext, file system
@heading @code{findnext}
@subheading Syntax

@example
#include <dir.h>

int findnext(struct ffblk *ffblk);
@end example

@subheading Description

This finds the next file in the search started by @code{findfirst}. @xref{findfirst}

@subheading Return Value

Zero if there was a match, else nonzero.

@c ----------------------------------------------------------------------
@node _fixpath, file system
@heading @code{_fixpath}
@subheading Syntax

@example
void _fixpath(const char *in_path, char *out_path);
@end example

@subheading Description

This function canonacalizes the input path @var{in_path} and stores the
result in the buffer pointed to by @var{out_path}.

The path is fixed by removing consecutive and trailing slashes, making
the path absolute if it's relative, removing "." components, collapsing
".." components, adding a drive specifier if needed, and converting all
slashes to '/'. 

@subheading Return Value

None.

@subheading Example

@example
char oldpath[100], newpath[100];
scanf(oldpath);
_fixpath(oldpath, newpath);
printf("that really is %s\n", newpath);
@end example