Why does the C preprocessor interpret the word "linux" as the constant "1"?

Why does the C preprocessor in GCC interpret the word linux (small letters) as the constant 1? test.c: #include <stdio.h> int main(void) { int linux = 5; return 0; } Result of $ gcc -E test.c (stop after the preprocessing stage): .... int main(void) { int 1 = 5; return 0; } Which of course yields an error. (BTW: There is no #define linux in the stdio.h file.)

[amagitakayosi]

1の代わりにlinux返そう

[yoppiblog]

歴史的経緯感じる

[takkaw]

そうなん