1assert(3C) Standard C Library Functions assert(3C)
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6 assert - verify program assertion
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9 #include <assert.h>
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11 void assert(int expression);
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15 The assert() macro inserts diagnostics into applications. When exe‐
16 cuted, if expression is FALSE (zero), assert() prints the error message
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18 Assertion failed: expression, file xyz, line nnn
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22 on the standard error output and aborts. In the error message, xyz is
23 the name of the source file and nnn the source line number of the
24 assert() statement. These are respectively the values of the preproces‐
25 sor macros __FILE__ and __LINE__.
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28 Since assert() is implemented as a macro, the expression may not con‐
29 tain any string literals.
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32 Compiling with the preprocessor option -DNDEBUG or with the preproces‐
33 sor control statement #define NDEBUG ahead of the #include <assert.h>
34 statement, will stop assertions from being compiled into the program.
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37 Messages printed from this function are in the native language speci‐
38 fied by the LC_MESSAGES locale category. See setlocale(3C).
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41 See attributes(5) for descriptions of the following attributes:
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46 ┌─────────────────────────────┬─────────────────────────────┐
47 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
48 ├─────────────────────────────┼─────────────────────────────┤
49 │Interface Stability │Committed │
50 ├─────────────────────────────┼─────────────────────────────┤
51 │MT-Level │Safe │
52 ├─────────────────────────────┼─────────────────────────────┤
53 │Standard │See standards(5). │
54 └─────────────────────────────┴─────────────────────────────┘
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57 abort(3C), gettext(3C), setlocale(3C), attributes(5), standards(5)
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61SunOS 5.11 30 Mar 2005 assert(3C)