# 记录执行gdb的过程 ## 例子 #include <stdio.h> #include <wchar.h> int main(void) { char str1[] = "abcd"; wchar_t str2[] = L"abcd"; return 0; } ## 技巧 用gdb调试程序时，可以使用“`set logging on`”命令把执行gdb的过程记录下来，方便以后自己参考或是别人帮忙分析。默认的日志文件是“`gdb.txt`”，也可以用“`set logging file file`”改成别的名字。以上面程序为例： (gdb) set logging file log.txt (gdb) set logging on Copying output to log.txt. (gdb) start Temporary breakpoint 1 at 0x8050abe: file a.c, line 6. Starting program: /data1/nan/a [Thread debugging using libthread_db enabled] [New Thread 1 (LWP 1)] [Switching to Thread 1 (LWP 1)] Temporary breakpoint 1, main () at a.c:6 6 char str1[] = "abcd"; (gdb) n 7 wchar_t str2[] = L"abcd"; (gdb) x/s str1 0x804779f: "abcd" (gdb) n 9 return 0; (gdb) x/ws str2 0x8047788: U"abcd" (gdb) q A debugging session is active. Inferior 1 [process 9931 ] will be killed. Quit anyway? (y or n) y 执行完后，查看log.txt文件： bash-3.2# cat log.txt Temporary breakpoint 1 at 0x8050abe: file a.c, line 6. Starting program: /data1/nan/a [Thread debugging using libthread_db enabled] [New Thread 1 (LWP 1)] [Switching to Thread 1 (LWP 1)] Temporary breakpoint 1, main () at a.c:6 6 char str1[] = "abcd"; 7 wchar_t str2[] = L"abcd"; 0x804779f: "abcd" 9 return 0; 0x8047788: U"abcd" A debugging session is active. Inferior 1 [process 9931 ] will be killed. Quit anyway? (y or n) 可以看到log.txt详细地记录了gdb的执行过程。 此外“`set logging overwrite on`”命令可以让输出覆盖之前的日志文件；而 “`set logging redirect on`”命令会让gdb的日志不会打印在终端。 参见[gdb手册](https://sourceware.org/gdb/onlinedocs/gdb/Logging-Output.html). ## 贡献者 nanxiao