20 lines
454 B
C++
20 lines
454 B
C++
// RUN: %clangxx -g %s -o %t && %run %t
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#include <assert.h>
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#include <stdio.h>
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int main(int argc, char **argv) {
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FILE *fp = fopen(argv[0], "r");
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assert(fp);
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// the file should be at least one character long, always
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assert(fgetc(fp) != EOF);
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// POSIX guarantees being able to ungetc() at least one character
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assert(ungetc('X', fp) != EOF);
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// check whether ungetc() worked
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assert(getc(fp) == 'X');
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assert(!fclose(fp));
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return 0;
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}
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