gcc -Wall -c "1.c" (在目录/home/tczf中)
编译失败
1.c:3: warning: return type defaults to ‘int’
1.c: In function ‘main’:
1.c:5: error: ‘for’ loop initial declarations are only allowed in C99 mode
1.c:5: note: use option -std=c99 or -std=gnu99 to compile your code
1.c:7: warning: implicit declaration of function ‘getch’