读写txt

abc1223@126.com
11222
aadad222@qq.com
1243444
vvv4444@qq.com
5444444

把邮箱的数字排除掉

#include <stdio.h>
#include <stdlib.h>

int main()
{
	FILE * fp = fopen("in.txt", "rb");
	if (fp == NULL)
	{
		fprintf(stderr, "cannot open file");
		exit(0);
	}

	FILE * wfp = fopen("out.txt", "w");
	if (wfp == NULL)
	{
		fprintf(stderr, "cannot open file");
		exit(0);
	}

	char buf[1024];
	char * p;
	bool isDigit = true;
	while (fgets(buf, 1024, fp))
	{
		isDigit = true;
		p = buf;
		while (p != '\0')
		{
			if ((*p) <'0' && (*p) > '9')
			{
				isDigit = false;
				break;
			}
			p++;
		}
		if (isDigit == true)
			fprintf(wfp, buf);
		else
			continue;
		fprintf(wfp, "\n");
	}
	fclose(fp);
	fclose(wfp);
	return 0;
}