generic delay() function
does anybody know, or know to code a function that makes the program halt for some time? like dos.h -> delay(int), just that i wished it was cross-platform.
i am working on a program that implies encrypting and decrypting data, and to prevent "users" from testing many keys with a file to find the right one, i wanted to set a one-second delay before the actual process.
This is an old-fashioned timing loop.
You are MUCH better off using OS-specific library routines. And doing a conditonal compile. This will suck up CPU for no good reason. In DOS it did not matter that much. Nowadays it does.
This waits a minimum of 1 second, probably more, if the seconds argument is 1. It also hogs the cpu.
Code:#include <time.h> #include <stdlib.h> void delay(time_t seconds) { time_t start=time(NULL); time_t end=0; seconds++; /* account for partial second */ for(;;) { end=time(NULL); if(seconds + end >= start) break; } }
i knew this variant, i was just wondering whether there was something else
well, i think i'll end up with precompiler options.
btw, how do you know whether you're doing a compile under windows or linux?
things in italics are things i don't know. maybe you can help.Code:#if (defined(windows) || defined(dos)) #include <dos.h> #define DELAY(x) delay(x) #else if defined(linux) #include <linux.h> #define DELAY(x) linux-equivalent-of-delay(x) #else error Only for Linux or DOS/Windows #endif #endif
Last edited by moonlord; 08-08-2005 at 10:53 AM.
Here's a start on what you want:
Code:#ifdef _WIN32 #include <dos.h> #define DELAY(x) wait(x) #else #include <unistd.h> #define DELAY(x) sleep(x) #endif
my compiler (borland c) doesn't seem to have a "wait" function, it's got a "delay" function instead, which they say it's "calibrated to 1ms". this makes me think it's just the infinite-for version.
1. i'm not using a win32 compiler, so that needs some adjustments.
2. unistd.h is supposed to be a cross-OS library? just asking because i don't have it.
3. how can you make visual studio.net 2002 to make a win16 program/project? i haven't managed.
1. download one for free - try DevC++. The FAQ, etc:Originally Posted by moonlord
http://www.bloodshed.net/dev/devcpp.html
2. unistd.h is purely unix, since you want to compile the code over there, you need the header file.
3. you can't AFAIK.
is there anything that's defined only for DOS and something else only for UNIX/Linux? like:
where _DOS and _UNIX_OR_LINUX are the things I'm asking for.Code:#ifdef _DOS #include <dos.h> #define DELAY(n) delay(n) #else #ifdef _WIN32 #include <dos.h> #define DELAY(n) wait(n) #else #ifdef _UNIX_OR_LINUX #include <unistd.h> #define DELAY(n) sleep(n) #else #error This program is designed only for DOS/Windows or UNIX/Linux #endif #endif #endif
Last edited by moonlord; 08-09-2005 at 06:43 AM.
7. It is easier to write an incorrect program than understand a correct one.
40. There are two ways to write error-free programs; only the third one works.*
10x all of you. i've solved the problem.
