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NED
Beta
Novice Errors Detection for C Programs

Start using NED now!

By using NED, you certify that you read, understood & agreed to the terms of usage.

Option #1 - Select files to upload

Use the file-browser below to select, one by one, all the .c or .h files in your project. Leave empty browsers if you do not need to analyze this many files. When you use the "Analyze" button, your files will be uploaded & analyzed. A new tab will open in your browser with a full report on possible errors.


Option #2 - Drag and Drop the files to upload

You might alternatively select a bunch of files in your file browser then drag and drop them here...

Drop Files Here to Upload

Option #3 - Upload a zip of your projet

You may alternatively zip your entire project folder then select the resulting zip file to upload


Things to keep in mind

This web app has been developed for Firefox. You may download a portable firefox version if you do not want to fully install it on your system. It should work on other standards-adhering browsing

Keep in mind these are potential errors, things you should take another look at in order to make sure they are not mistakes. Unfortunately, there is so much a program may do to understand another program.

Do not hesitate to drop us feedback, see about details here. If you want to learn a bit more about this project read here

Search through our tutorials

This table lists all our tutorials so you may peruse through them. The number of views for each is also displayed; this is not the number of times the error occured in an uploaded set of files but rather the number of times a user clicked on the messages hyperlinked to this tutorial in order to read it.

Similarly, the usefulness is based on the number of users who clicked yes at the bottom of a tutorial page. The uselessness is based on the number of those who clicked no.

The Freq. value represents how often the errors or warnings which the tutorial explains have been found during uploaded files analysis. It is a good estimate of the frequency of the underlying bugs among all NED users

Do not hesitate to use the mini-survey feature which you will find in the last section of each tutorial page. It helps identify both the tutorials in need of improvement but also those we should use as models.

Name From Type Details Views Useful Useless Freq.
Unused VariablesCompilerWarningVariable declared, maybe even assigned, but never used551012209
Undeclared VariablesCompilerErrorUndeclared variable used49922586
Undefined ReferencesLinkerErrorUndefined reference to function or variable43711
Missing Return StatementAnalyzerWarningFunction is missing return statement44610175
Missing Array SizeCompilerErrorThe size of an array is not specified3901194
Empty BlockAnalyzerWarningYour program features an empty block42112288
Single Quote StringCompilerWarningUsing single quote as string delimiter41053123
Unexpected Break StatementAnalyzerWarningUnexpected break statement4020089
Missing break statementAnalyzerWarningMissing break statement40883
Unreachable StatementsAnalyzerWarningUnreachable statements41517179
= vs. ==CompilerWarningAssignment used in Boolean expression46821527
Unary OPs in Larger ExprAnalyzerWarningUnary operators used in larger expression41300528
Bitwise vs. LogicalAnalyzerWarningUse of bitwise binary operator instead of logical operator41401386
Expected SemicolonCompilerErrorExpected semi-colon5242194
Dangling PointerAnalyzerWarningDangling pointer40731172
Dereferencing NULLAnalyzerWarningDereferencing NULL pointer4472595
Dereferencing Incomplete TypesCompilerErrorDereferencing a pointer to an incomplete data type41433461
Multi-free on same memory blockAnalyzerWarningFreeing multiple times the same memory block4070187
Memory LeakAnalyzerWarningMemory leak41304254
Freeing unallocated pointerAnalyzerWarningFreeing non-allocated memory41022171
sizeof on PointerAnalyzerWarningUsing sizeof operator on pointer40212
Uninitialized PointersAnalyzerWarningUnitialized pointer38116
Discarding Ptrs QualifiersCompilerWarningAssignment or cast discards pointers qualifier44511
Unchecked MallocAnalyzerWarningReturn value from malloc or similar function is not checked41201503
Unexpected EOFCompilerErrorUnexpected EOF4103397
Unterminated literalCompilerErrorMissing end-delimiter for character or string literal63421617
Useless ValueAnalyzerWarningStatement results in a value which is never used43431726
Void not IgnoredCompilerErrorAttempting to use a void returned value44706109
Missing EOF NewlineCompilerWarningMissing newline at end of file40830
Multiple Unary Ops on VariableCompilerWarningUsing multiple unary operators on same variable in a single expression42303300
Empty Char LiteralCompilerErrorEmpty character literal42332104
Using Uninitialized VariableCompilerWarningVariable not initialized46922104
Forward Parameter DeclarationCompilerErrorParameter has a forward-declaration422031708
Unexpected Data TypesCompilerErrorUnexpected multiple data types where one is expected41403275
Unexpected Arguments NumberCompilerErrorUnexpected number of arguments41410186
Mismatch numbers for args / specifiersCompilerWarningThere is a mismatch between the number of format specifiers used in a printf or scanf, and their arguments40321392
Mismatch types for args / specifiersCompilerWarningThere is a mismatch between the data type of format specifiers used in a printf or scanf, and the data type of the corresponding argument51322622
Using unknwon struct fieldCompilerErrorUnknown struct field45220196
Parameters Storage ClassCompilerErrorStorage class specified for parameter4112099
Shadowed IdentifierAnalyzerWarningShadowing variable already in scope3912171
Argument ConversionCompilerWarningArguments data type is converted41220580
Modifying ParametersAnalyzerWarningFormal parameters are assigned inside function39420182
Assign Integer to PointerCompilerWarningAssigning non-NULL constant to Pointer42301288
Mixed Pointers DeclarationsAnalyzerWarningDeclaring variables in one statement with pointer and non-pointer data types39220
Missing Function DeclarationCompilerWarningMissing function declaration56031
Function should not be exportedAnalyzerWarningFunction is not static to its file, yet unused in other files409301295
Off by oneAnalyzerWarningA loop might be off by one in its number of iteration; e.g. start at 0 instead of 13780061
Formatting String MismatchAnalyzerWarningA printf or scanf is using a formatting string with conversion specifiers unrelated to the parameters39801
Assign pointer to integerAnalyzerWarningAssigning memory address to variable expecting integer39900205
33100
43700
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36900
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