Eroare de compilare: user.c: In function ‘main’: user.c:32: error: ‘for’ loop initial declarations are only allowed in C99 mode user.c:32: note: use option -std=c99 or -std=gnu99 to compile your code user.c:36: warning: unused variable ‘tx’ user.c:42: error: conflicting types for ‘i’ user.c:32: note: previous definition of ‘i’ was here user.c:42: error: ‘for’ loop initial declarations are only allowed in C99 mode user.c:14: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:15: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:18: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:23: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:25: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:33: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:35: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result