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POFingerprint calls cause segfaults in c++
 

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  1. POFingerprint calls cause segfaults in c++
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    <p>I'm trying to write a simple fingerprint scanning program in c++ using libfprint, however it intermittently segfaults when run. Valgrind says the error is in the call to fp_enroll_finger which is consistent with my debugging, however beyond that I have absolutely no idea what is causing this error. Some of the times the program is run its fine, but some times it seems to consistently segfault for a period of time whenever the program is run? Heres the code:</p> <pre><code>#include &lt;iostream&gt; extern "C" { #include &lt;libfprint/fprint.h&gt; } using namespace std; fp_dev * fpdev; fp_print_data ** fpdata; bool createDevice(); int main(int argc, char **argv) { int r = fp_init(); if(r != 0) { return r; } while(createDevice()) { cout &lt;&lt; "Scan right index finger" &lt;&lt; endl; int enrollStatus = fp_enroll_finger(fpdev, fpdata); if(enrollStatus != 1) { cout &lt;&lt; "Bad scan" &lt;&lt; endl; fp_dev_close(fpdev); } else { cout &lt;&lt; "Good scan" &lt;&lt; endl; fp_print_data_save(fpdata[0], RIGHT_INDEX); break; } } if(fpdev != NULL) { fp_dev_close(fpdev); } fp_exit(); return 0; } bool createDevice() { fp_dscv_dev ** listOfDiscoveredDevs; fp_dscv_dev * discoveredDevice; listOfDiscoveredDevs = fp_discover_devs(); discoveredDevice = listOfDiscoveredDevs[0]; if(discoveredDevice != NULL) { cout &lt;&lt; "Device found" &lt;&lt; endl; fpdev = fp_dev_open(discoveredDevice); } else { cout &lt;&lt; "No device found" &lt;&lt; endl; return false; } fp_dscv_devs_free(listOfDiscoveredDevs); return true; } </code></pre>
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    1. USGeorge Broughton
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    1. CODoes fpdata need data allocated to it? Also, after you close fpdev, set it to NULL. Otherwise, you will end up closing it twice when `fp_enroll_finger` does not return 1.
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      1. POFingerprint calls cause segfaults in c++
      1. USjeffmagill
 

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