How To Correctly Output of Struct Objects

**NuNn** · 02-13-2009

I am having trouble displaying items such as the and Size of a file when I access the stat() function.

http.c:234: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘__off_t’

The same goes from when I try obtain the date using the struct tm and try to assign it to a buffer to be written to a client socket using:

Code:

	time_t tm;
	tm = time(NULL);
	ptr = localtime(&tm);
       sprintf(buf, "%s", ptr);

I get:

http.c:233: warning: format ‘%s’ expects type ‘char *’, but argument 2 has type ‘__time_t’

How would I set the arguments up or cast these items so I no longer have these issues. Thanks

**Elysia** · 02-13-2009

They return structs filled with information. You have to pick what you want to know from the struct.

**NuNn** · 02-13-2009

I need to know the file size and last modification time as well as the well date today. I know that file size type is off_t and modification is of type time_t. How would I go about writing these to the screen or saving them correctly to my buffer to be outputted?

**Elysia** · 02-13-2009

Members in the struct passed to stat:

st_mtime
Time of last modification of file.

st_size
Size of the file in bytes; a 64-bit integer for variations with the i64 suffix.

As well, time_t is an int or a long, I believe.

**matsp** · 02-13-2009

Originally Posted by NuNn

I need to know the file size and last modification time as well as the well date today. I know that file size type is off_t and modification is of type time_t. How would I go about writing these to the screen or saving them correctly to my buffer to be outputted?

You can either print the individual parts of the date/time structure returned by localtime() - it has fields like year, minute and such. Or you could use for example strftime() which will make a string from a time parameter - similar to sprintf(), but you have different "%..." parameters describing how to format the time-string (so you can have 2009-Jan-21 or 01/21/2009, for example).

--
Mats

**IceBall** · 02-13-2009

localtime( ) will return a struct tm*

struct tm is defined as

Code:

struct tm {
    int tm_sec;         /* seconds */
    int tm_min;         /* minutes */
    int tm_hour;        /* hours */
    int tm_mday;        /* day of the month */
    int tm_mon;         /* month */
    int tm_year;        /* year */
    int tm_wday;        /* day of the week */
    int tm_yday;        /* day in the year */
    int tm_isdst;       /* daylight saving time */
};

to print a time e.g.

Code:

printf("%d:%d", ptr->tm_hour, prt->tm_min);

**Elysia** · 02-13-2009

Oh yes, it wants a time_t as argument. Dang C functions. Sometimes so confusing and so difficult to use.

**NuNn** · 02-13-2009

Thank you guys very much

, is there an issue with the tm_year variable as I am getting "109" as my year each time? Maybe y2k? lol

**Elysia** · 02-13-2009

MSDN says:

Year (current year minus 1900).

**NuNn** · 02-13-2009

Alrighty, I have the time working appropriately but I am still having trouble with my stat output.

Originally Posted by Elysia

Members in the struct passed to stat:

st_mtime
Time of last modification of file.

st_size
Size of the file in bytes; a 64-bit integer for variations with the i64 suffix.

As well, time_t is an int or a long, I believe.

I have tried printf() with the signed decimal and floating point tags for both the file modification time and size but still am not receiving the proper output. What are the flags or cast which I need to use?:

**matsp** · 02-13-2009

Originally Posted by NuNn

Alrighty, I have the time working appropriately but I am still having trouble with my stat output.

I have tried printf() with the signed decimal and floating point tags for both the file modification time and size but still am not receiving the proper output. What are the flags or cast which I need to use?:

Like discussed above, file modification time is a time_t type. Size will be a type off_t, which I expect is a "long long", which you would output with "%lld" or some such.

--
Mats

Thread: How To Correctly Output of Struct Objects

Thread Tools

Search Thread

Display

How To Correctly Output of Struct Objects

Similar Threads

Need help with linked list sorting function

What's wrong with my search program?

Search Engine - Binary Search Tree

Request for comments

Output problems with structures