Databases
StackOverflow2013
Postsdbo
POprintf of a size_t variable with lld, ld and d type identifiers
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POprintf of a size_t variable with lld, ld and d type identifiers
    primarykey
    data
    text
    <p>I wrote this tiny code:</p> <pre><code>#include &lt;stdio.h&gt; int main() { size_t temp; temp = 100; printf("lld=%lld, ld=%ld, u=%u\n", temp, temp, temp); return 0; } </code></pre> <p>I am running this on a <strong>i386 GNU/Linux</strong> machine with <strong>gcc version 4.1.1 20070105 (Red Hat 4.1.1-52)</strong>. This is the output that I got:</p> <pre><code>lld=429496729700, ld=100, u=7993461 </code></pre> <p>I can understand that the first (<code>lld</code>) was printed as garbage because the <code>printf</code> tries to print 8 bytes (for <code>signed long long</code> as signified by <code>lld</code>) when only 4 bytes are available from variable <code>temp</code>. But, I fail to understand why the last identifier, <code>u</code> is getting printed as garbage - whereas, in my understanding this is the closest applicable identifier for <code>size_t</code>.</p> <p>Here I have assumed that <code>size_t</code> is <code>unsigned int</code> (which is signed 4 bytes for my i386).</p> <p>Now, I did a little tweaking with the <code>printf</code> line:</p> <pre><code>... printf("ld=%ld, u=%u, lld=%lld\n", temp, temp, temp); ... </code></pre> <p>and I have a perfectly fine answer (except the <code>lld</code> part).</p> <pre><code>ld=100, u=100, lld=34331653576851556 </code></pre> <p>Can someone please help me in understanding what exactly am I missing here?</p> <p>Thanks a lot for any help!</p> <p><em>[side note: I tried switching optimization using <code>gcc -O[0,2]</code> tag on/off without any difference in the observation.]</em></p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USShrey
    plurals
    1. This table or related slice is empty.
    1. PL
      singulars
      1. LTLinked
    2. PL
      singulars
      1. LTLinked
    3. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POprintf of a size_t variable with lld, ld and d type identifiers
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POprintf of a size_t variable with lld, ld and d type identifiers
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POprintf of a size_t variable with lld, ld and d type identifiers
      1. This table or related slice is empty.
      1. VTUpMod
    1. COThe -Wformat option will probably detect this incompatibility for you.
      singulars
      1. POprintf of a size_t variable with lld, ld and d type identifiers
      1. USClifford
    2. CO@Clifford Thanks for the input - but, I was deliberately using wrong specifiers. I actually wanted to know how `printf` was consuming the elements on the stack. In fact, I think -Wall would have the same thing as well. Nevertheless, thanks a lot.
      singulars
      1. POprintf of a size_t variable with lld, ld and d type identifiers
      1. USShrey
    3. COI realise that it was deliberate; but my point was that if the intention was to observe the compiler's behaviour, the -Wformat option demonstrates alternative (and safer) behaviour, which may have been of interest to someone, even if you were already aware of it. -Wall did not include -Wformat on older versions of GCC.
      singulars
      1. POprintf of a size_t variable with lld, ld and d type identifiers
      1. USClifford
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload