指向30 MB文件的指针 [英] Pointer to a 30 MB file
问题描述
while（1）
{
fgets（temp_string，MAXLEN，auctioneer_lua）;
/ *检查我们do ave一个有效的数据输入文件* /
if（strstr（temp_string，" AuctioneerHistoryDB"））
{
/ *这是一个有效的文件* /
printf（"％s\ n"，temp_string）;
j = items_list（auctioneer_lua）;
// j = read_auctioneer_lua（source_file_name）;
休息;
}
/ *许多其他东西* /
}
这个测试工作正常但它传递指针的位置是
" AuctioneerHistoryDB"找到。
除了在文件顶部搜索toekn之外，还有一种方法
将指针重置为文件顶部没有关闭和
重新打开它？
while (1)
{
fgets(temp_string, MAXLEN, auctioneer_lua);
/* check that we do ahve a valid data input file */
if (strstr(temp_string, "AuctioneerHistoryDB"))
{
/* this is a valid file */
printf("%s\n", temp_string);
j = items_list(auctioneer_lua);
// j = read_auctioneer_lua(source_file_name);
break;
}
/* lots of other stuff */
}
This test works fine BUT it passes on the pointer with the line where
"AuctioneerHistoryDB" is found.
Other than searching for a toekn at the top of the file, is ther a way
to reset the pointer to the top of the file without closing and
re-opening it?
推荐答案
pkirk25写道：
[snip]
pkirk25 wrote:
[snip]
除了在文件顶部搜索toekn之外，还有其他方式
将指针重置为文件顶部而不关闭，并重新打开它？
重新打开它？
Other than searching for a toekn at the top of the file, is ther a way
to reset the pointer to the top of the file without closing and
re-opening it?
看一下rewind（）函数。您可能还会发现
fseek / ftell和fgetpos / fsetpos函数很有用。
Robert Gamble
Take a look at the rewind() function. You may also find the
fseek/ftell and fgetpos/fsetpos functions useful.
Robert Gamble
Robert Gamble写道：
Robert Gamble wrote:
pkirk25写道：
[ snip]
pkirk25 wrote:
[snip]
除了在文件顶部搜索toekn之外，还有一种方法
将指针重置为顶部没有关闭的文件和
重新打开它？
Other than searching for a toekn at the top of the file, is ther a way
to reset the pointer to the top of the file without closing and
re-opening it?
看一下rewind（）函数。您可能还会发现
fseek / ftell和fgetpos / fsetpos函数很有用。
Robert Gamble
Take a look at the rewind() function. You may also find the
fseek/ftell and fgetpos/fsetpos functions useful.
Robert Gamble
2个相同代码的文件
char * temp_string = malloc（254）;
rewind（auctioneer_lua）;
fgets（temp_string，MAXLEN，auctioneer_lua）;
printf（请再试一次）;
返回0;
在1中，这会导致立即崩溃 - printf永远不会出现。在
其他，它工作正常。
叹气 - 休息时间。
2 files with identical code
char *temp_string = malloc(254);
rewind(auctioneer_lua);
fgets(temp_string, MAXLEN, auctioneer_lua);
printf("Please try again\n");
return 0;
In 1, this causes immediate crash - the printf never appears. In the
other, it works fine.
Sigh - time for a break.
pkirk25写道：
pkirk25 wrote:
char * temp_string = malloc（254）;
rewind（auctioneer_lua）;
fgets（temp_string，MAXLEN，auctioneer_lua）;
printf（请再试一次）;
返回0;
在1中，这会导致立即崩溃 - printf永远不会出现。在
其他，它工作正常。
叹气 - 休息时间。
char *temp_string = malloc(254);
rewind(auctioneer_lua);
fgets(temp_string, MAXLEN, auctioneer_lua);
printf("Please try again\n");
return 0;
In 1, this causes immediate crash - the printf never appears. In the
other, it works fine.
Sigh - time for a break.
更合适的是，休息和调试器。
如果您没有在编写的代码中轻松发现内容 - 你需要踩过调试器，直到你强制错误为止。还有其他的东西
是一个痛苦的教训。
More appropriately, a break AND a debugger.
If you''re not spotting things easily in the written code - you need to
be stepping through a debugger until you force the error. Anything else
is a lesson in pain.
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