| 1 | // RUN: %clangxx -g %s -o %t && %run %t |
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| 2 | |
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| 3 | #include <assert.h> |
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| 4 | #include <stdio.h> |
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| 5 | |
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| 6 | int main(int argc, char **argv) { |
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| 7 | FILE *fp = fopen(filename: argv[0], modes: "r" ); |
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| 8 | assert(fp); |
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| 9 | |
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| 10 | // the file should be at least one character long, always |
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| 11 | assert(getc_unlocked(fp) != EOF); |
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| 12 | // POSIX guarantees being able to ungetc() at least one character |
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| 13 | // NB: ungetc_unlocked is apparently not present |
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| 14 | assert(ungetc('X', fp) != EOF); |
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| 15 | // check whether ungetc() works with getc_unlocked() |
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| 16 | assert(getc_unlocked(fp) == 'X'); |
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| 17 | |
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| 18 | assert(!fclose(fp)); |
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| 19 | return 0; |
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| 20 | } |
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| 21 | |
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