19.1 How can I read a single character from the keyboard without waiting for the RETURN key? How can I stop characters from being echoed on the screen as they're typed?
19.2 How can I find out if there are characters available for reading (and if so, how many)? Alternatively, how can I do a read that will not block if there are no characters available?
19.3 How can I display a percentage-done indication that updates itself in place, or show one of those ``twirling baton'' progress indicators?
How can I clear the screen?
How can I print text in color?
How can I move the cursor to a specific x, y position?
19.4b I'm compiling some test programs on a windows-based system, and the windows containing my program's output are closing so quickly after my program calls exit that I can't see the output. How can I make it pause before closing?
19.5 How do I read the arrow keys? What about function keys?
19.6 How do I read the mouse?
19.7 How can I do serial (``comm'') port I/O?
19.8 How can I direct output to the printer?
19.9 How do I send escape sequences to control a terminal or other device?
19.9b How can I access an I/O board directly?
19.10 How can I do graphics?
19.10b How can I display GIF and JPEG images?
19.10c How can I load new fonts for display?
19.10d How can I send mail from within a C program?
19.11 How can I check whether a file exists? I want to warn the user if a requested input file is missing.
19.12 How can I find out the size of a file, prior to reading it in?
19.12b How can I find the modification date and time of a file?
19.13 How can a file be shortened in-place without completely clearing or rewriting it?
19.14 How can I insert or delete a line (or record) in the middle of a file?
19.15 How can I recover the file name given an open stream or file descriptor?
19.16 How can I delete a file?
19.16b How do I copy files?
19.17 Why can't I open a file by its explicit path? The call
fopen("c:\newdir\file.dat", "r")is failing.
19.17b fopen isn't letting me open files like "$HOME/.profile" and "~/.myrcfile".
19.17c How can I suppress the dreaded MS-DOS ``Abort, Retry, Ignore?'' message?
19.18 I'm getting an error, ``Too many open files''. How can I increase the allowable number of simultaneously open files?
19.19 How can I find out how much free space is available on disk?
19.20 How can I read a directory in a C program?
How do I create a directory?
How do I remove a directory (and its contents)?
19.22 How can I find out how much memory is available?
19.23 How can I allocate arrays or structures bigger than 64K?
19.24 What does the error message ``DGROUP data allocation exceeds 64K'' mean, and what can I do about it? I thought that using large model meant that I could use more than 64K of data!
How can I access memory
(a memory-mapped device,
or graphics memory)
located at a certain address?
How can I do PEEK and POKE in C?
19.25b How can I determine whether a machine's byte order is big-endian or little-endian?
19.26 How can I access an interrupt vector located at the machine's location 0? If I set a pointer to 0, the compiler might translate it to some nonzero internal null pointer value.
19.27 How can I invoke another program (a standalone executable, or an operating system command) from within a C program?
19.28 How can I call system when parameters (filenames, etc.) of the executed command aren't known until run time?
19.29 How do I get an accurate error status return from system on MS-DOS?
19.30 How can I invoke another program or command and trap its output?
19.31 How can my program discover the complete pathname to the executable from which it was invoked?
19.32 How can I automatically locate a program's configuration files in the same directory as the executable?
19.33 How can a process change an environment variable in its caller?
19.34 How can I open files mentioned on the command line, and parse option flags?
19.35 Is exit(status) truly equivalent to returning the same status from main?
19.36 How can I read in an object file and jump to locations in it?
19.37 How can I implement a delay, or time a user's response, with sub-second resolution?
19.38 How can I trap or ignore keyboard interrupts like control-C?
19.39 How can I handle floating-point exceptions gracefully?
19.39b How can I ensure that integer arithmetic doesn't overflow?
19.40 How do I... Use sockets? Do networking? Write client/server applications?
19.40a Can I combine .OBJ and .LIB files from Microsoft C and Turbo C?
19.40b How do I... Use BIOS calls? Write ISR's? Create TSR's?
19.40c I'm trying to compile this program, but the compiler is complaining that ``union REGS'' is undefined, and the linker is complaining that int86 is undefined.
19.40d What are ``near'' and ``far'' pointers?
19.41 But I can't use all these nonstandard, system-dependent functions, because my program has to be ANSI compatible!
19.42 Why isn't any of this standardized in C? Any real program has to do some of these things.
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