Compilare: user.c: In function ‘main’: user.c:9:36: warning: unused variable ‘p’ [-Wunused-variable] char *line1, *c, a[100], b[100], *p, *line2, ch; ^ user.c:9:27: warning: unused variable ‘b’ [-Wunused-variable] char *line1, *c, a[100], b[100], *p, *line2, ch; ^ user.c:9:19: warning: unused variable ‘a’ [-Wunused-variable] char *line1, *c, a[100], b[100], *p, *line2, ch; ^ user.c:14:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%c", &ch); ^ user.c:20:10: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%c", &ch); ^ user.c:23:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%c", &ch); ^ user.c:27:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%c", &ch); ^ user.c:28:10: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%c", &ch); ^ user.c:30:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%c", &ch); ^ user.c:32:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%c", &ch); ^ user.c:34:12: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%c", &ch); ^ user.c:35:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%c", &ch); ^