sscanf read int from strings of "image_00021"

Hi all,

I have a database of files that I am reading in and working on with the titles created by:

Code:

---

...
ugv++;
sprintf(input_file, "UGV_%i/image_%05d.jpg", ugv, img_num)
...

---

This creates a list of files like this, which I need to be ordered so I can sort the files easily in the folder:
image_00001.jpg
image_00002.jpg
...
image_00009.jpg
image_00010.jpg
image_00011.jpg

I can read in the titles of these files easily enough, but because the integers I want (1,2,...9,10,11) are preceded by an unknown number of zeroes, reading in the desired number is much more difficult than if you have a known position of an integer.

My code currently is:

Code:

---

int latestImgNo;
sscanf(imgString, "%*c%05d", latestImgNo);

---

But I get the warning:
warning: format '%05d' expects type 'int*', but argument 3 has type 'int'

I have tried making latestImgNo a pointer, but it gives the same sorts of errors.

I have tried looking up delimeters, but that doesn't really help (as far as I know) because I don't know how many zeroes to search past.

Should I use something to convert "00021" as a string to an integer, that would just ignore zeroes?

Thanks for any suggestions

To think it was this easy...

My problems were:

1. sscanf is a function! Therefore, quoting from :
"These arguments are expected to be references (pointers): if you want to store the result of a sscanf operation on a regular variable you should precede its identifier with the reference operator, i.e. an ampersand sign (&)". So I added an & before latestImgNo.

2. I needed to understand the modifier part of sscanf()

sscanf = %[*][width][modifiers]type

From http://www.opengroup.org/onlinepubs/...ons/scanf.html

Each conversion specification is introduced by the character '%' or the character sequence "%n$", after which the following appear in sequence:

• An optional assignment-suppressing character '*'.
• An optional non-zero decimal integer that specifies the maximum field width.
• An option length modifier that specifies the size of the receiving object.
• A conversion specifier character that specifies the type of conversion to be applied.

So that's it. I needed %5d not %05d as you need with sprintf(), and %*6c not %*c which I think just read the first character (not sure on this). The '*' as above in the first dot point means you read the character/int/whatever, but don't assign it to a variable

So the code that worked was

Code:

---

int latestImgNo;
sscanf(imgString, "%*6c%5d", &latestImgNo);

---

Hopefully that helps others!