The append keyword applies to all dump styles except cfg and xtc and dcd. It also applies only to text output files, not to binary or gzipped or image/movie files. If specified as yes, then dump snapshots are appended to the end of an existing dump file. If specified as no, then a new dump file will be created which will overwrite an existing file with the same name.翻译成中文
时间: 2023-02-26 12:03:09 浏览: 66
"append" 关键字适用于除了 cfg、xtc 和 dcd 之外的所有转储样式。它仅适用于文本输出文件,不适用于二进制或 gzipped 或图像/电影文件。如果指定为 yes,则转储快照将追加到现有转储文件的末尾。如果指定为 no,则将创建一个新的转储文件,它将覆盖具有相同名称的现有文件。
相关问题
Learn about the O_APPEND flag of open(). Please write a program to append one file to another file with open() and lseek().
Sure, here's an example program that appends one file to another using the O_APPEND flag of open() and lseek():
```
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
int main(int argc, char *argv[]) {
if (argc != 3) {
fprintf(stderr, "Usage: %s <source file> <destination file>\n", argv[0]);
exit(EXIT_FAILURE);
}
int src_fd = open(argv[1], O_RDONLY);
if (src_fd == -1) {
perror("open");
exit(EXIT_FAILURE);
}
int dest_fd = open(argv[2], O_WRONLY | O_CREAT | O_APPEND, 0644);
if (dest_fd == -1) {
perror("open");
exit(EXIT_FAILURE);
}
off_t offset = lseek(dest_fd, 0, SEEK_END);
if (offset == -1) {
perror("lseek");
exit(EXIT_FAILURE);
}
char buf[BUFSIZ];
ssize_t nread;
while ((nread = read(src_fd, buf, sizeof(buf))) > 0) {
ssize_t nwritten = write(dest_fd, buf, nread);
if (nwritten == -1) {
perror("write");
exit(EXIT_FAILURE);
}
}
if (nread == -1) {
perror("read");
exit(EXIT_FAILURE);
}
if (close(src_fd) == -1) {
perror("close");
exit(EXIT_FAILURE);
}
if (close(dest_fd) == -1) {
perror("close");
exit(EXIT_FAILURE);
}
return 0;
}
```
This program takes two command-line arguments: the source file to append and the destination file to append to. It opens the source file for reading and the destination file for writing with the O_APPEND flag, which ensures that all writes will be appended to the end of the file. It then seeks to the end of the destination file to get the current offset, reads from the source file in chunks and writes them to the destination file, and finally closes both files.
forever 启动项目报错 log file /root/.forever/forever.log exists. Use the -a or --append option to append log
这个错误提示是因为你使用 `forever start` 命令启动项目时,forever 日志文件 `/root/.forever/forever.log` 已经存在了。
你可以使用 `-a` 或 `--append` 选项来将日志追加到现有的日志文件中,即:
```
forever start -a your_script.js
```
或者,你也可以删除原来的日志文件,再重新启动项目,即:
```
rm /root/.forever/forever.log
forever start your_script.js
```
这样应该就能顺利启动项目了。