查找树，俄罗斯方块，系统编程开始

Chapter13/io/stdio/fopen.c

@@ -0,0 +1,29 @@
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main()
+{
+    FILE *fp;
+
+    fp = fopen("tmp", "r");
+    if (NULL == fp)
+    {
+        // fprintf(stderr, "fopen() failed!   errno = %d\n", errno);
+        // out: fopen() failed!   errno = 2
+        /* errno:定义路径 /usr/include/asm-generic/errno-base.h */
+
+        // perror("fopen()");
+        // out: fopen(): No such file or directory
+
+        fprintf(stderr, "fopen(): %s\n", strerror(errno));
+        // out: fopen(): No such file or directory
+
+        exit(1);
+    }
+
+    puts("OK!");
+
+    exit(0);
+}