Hi there everybody.
I'd like to be able to supply my program with a drive letter, and have the program use the system() function on this target drive (like a batch file). The below is an example of what I've tried, but the system() line errors.
Sorry for the stupid question!Code:char drive[1]; printf("Target drive is: "); scanf("%s", drive); printf("\nOkay, using %s: as target drive...\n", drive); system("dir %s:", drive); system("PAUSE");
> char drive[1];
This isn't large enough to hold a string input from scanf %s
> system("dir %s:", drive);
Use sprintf() to construct the command line, then use the result of that with system()
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
Use sprintf before calling system.
Code:char input[10], drive[10]; char command[100]; printf("Target drive is: "); fgets(input, 10, stdin); if (sscanf(input, "%s", drive) != 1) { printf("Error entering target drive."); return EXIT_FAILURE; } printf("\nOkay, using %s: as target drive...\n", drive); sprintf(command, "dir %s:", drive); system(command); system("PAUSE");
Thank you kindly guys, I get it now.
One more follow up question about system(); guys....
when I do a
from the command line it just goes without an problems. However if I try the same thing in this program by goingCode:copy C:\directory\file.txt I:\directory
it thinks for a second and then just says "0 files copied". What gives? It should work as if it was from the command line, right? Thanks!Code:sprintf(command, "copy C:\directory\file.txt %s:\directory", drive); system(command);
(I know there's a much easier way to copy files in C, this is just an example!)
Try forward slashes in string literals. Otherwise escape backslashes as \\.
[edit]printf("command = \"%s\"\n", command); /* debugging */
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.*
