访问大文件

//访问大文件
#define _LARGEFILE64_SOURCE
#include <sys/stat.h>
#include <fcntl.h>
#include "tlpi_hdr.h"
#define EXIT_SUCESS 0int
main(int argc, char *argv[])
{int fd;off64_t off;if (argc != 3 || strcmp(argv[1],"--help") == 0)usageErr("%s pathname offset\n",argv[0]);fd = open64(argv[1],O_RDWR|O_CREAT,S_IRUSR | S_IWUSR);if (fd == -1)errExit("open64");off = atoll(argv[2]);if (lseek64(fd,off,SEEK_SET) == -1)errExit("lseek64");if (write(fd,"test",4) == -1)errExit("write");exit(EXIT_SUCESS);
}
/*程序测试示例:[root@localhost linux-test]# gl++ test.c
[root@localhost linux-test]# echo "hello world" > a.txt
[root@localhost linux-test]# cat a.txt
hello world
[root@localhost linux-test]#  ./a.out a.txt "hello world"
[root@localhost linux-test]# cat a.txt
testo world*/