#include <stdio.h> 
#include <string.h> 
#include <stdlib.h> 
#ifdef __linux__ 
#include <sys/stat.h> 
#include <unistd.h> 
#elif defined(__sgi) 
#include <sys/types.h> 
#include <sys/stat.h> 
#include <fcntl.h> 
#endif 

int main(int argc, char *argv[]) 
{ 
        struct stat target; 
        char ext[] = ".old"; 
        char *newfile; 
        size_t length; 
        int rotatesize; 

        if (argc != 3) 
        { 
                fprintf(stderr, "Usage: %s <file> <value>\n", argv[0]); 
                fprintf(stderr, "   <file> is the name of the file to rotate.\n"); 
                fprintf(stderr, "   <value> is the size (in bytes) the file must\n"); 
                fprintf(stderr, "           be greater than for rotation.\n"); 
                exit(-1); 
        } 

        if (stat(argv[1], &target)) 
        { 
                perror("Unable to open file"); 
                exit(-1); 
        } 

        rotatesize = atoi(argv[2]); 
        if (rotatesize <= target.st_size) 
        { 
                length = strlen(argv[1]); 
                if ((newfile = (char *) malloc(length * sizeof(char))) == NULL) 
                { 
                        fprintf(stderr, "Malloc failed, don't ask me why.\n"); 
                        exit(-1); 
                } 

                strcpy(newfile, argv[1]); 
                strcat(newfile, ext); 

                if (rename(argv[1], newfile)) 
                { 
                        perror("Error renaming original file"); 
                        exit(-1); 
                } 

                if ((creat(argv[1], target.st_mode)) < 0) 
                { 
                        perror("Error creating new file"); 
                        exit(-1); 
                } 
                exit(0); 
        } 

        else 
        { 
                exit(1); 
        } 
}