10-07-2004
Quote:
Originally posted by Driver
> If you have the memory, you might want to read the whole file into memory, manipulate it there and then dump the results back to disk.
Well, if one really wants to modify it in memory, one could also mmap() the file. Using MAP_SHARED you won't need any memory to back the file, as it is already done by the disk. memmove() to move data to make room/overwrite areas of the file and ftruncate() to grow/shrink the file. But I do not recommend this because it likely does not buy anything and may well be slower, requires more effort and decreases the degree of portability.
Yes, I agree, which is why I say "could". A lot depends on machine specs and the problem itself. The problem described is quite simple, but a mail merge application, indexing or sorting application will require due consideration to performance.
My point to the OP was quite simple and old fashioned: memory is faster than disk!
( I hope that is still true these days
)
Peace
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has_ic(3XCURSES) X/Open Curses Library Functions has_ic(3XCURSES)
NAME
has_ic, has_il - determine insert/delete character/line capability
SYNOPSIS
cc [ flag... ] file... -I /usr/xpg4/include -L /usr/xpg4/lib
-R /usr/xpg4/lib -lcurses [ library... ]
c89 [ flag... ] file... -lcurses [ library... ]
#include <curses.h>
bool has_ic(void);
bool has_il(void);
DESCRIPTION
The has_ic() function determines whether or not the terminal has insert/delete character capability.
The has_il() function determines whether or not the terminal has insert/delete line capability.
RETURN VALUES
The has_ic() function returns TRUE if the terminal has insert/delete character capability and FALSE otherwise.
The has_il() function returns TRUE if the terminal has insert/delete line capability and FALSE otherwise.
ERRORS
None.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
|MT-Level |Unsafe |
+-----------------------------+-----------------------------+
SEE ALSO
libcurses(3XCURSES), attributes(5), standards(5)
SunOS 5.10 5 Jun 2002 has_ic(3XCURSES)