# 記錄執行gdb的過程 ## 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調試程序時，可以使用“`set logging on`”命令把執行gdb的過程記錄下來，方便以后自己參考或是別人幫忙分析。默認的日志文件是“`gdb.txt`”，也可以用“`set logging file file`”改成別的名字。以上面程序為例： (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 執行完后，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詳細地記錄了gdb的執行過程。 此外“`set logging overwrite on`”命令可以讓輸出覆蓋之前的日志文件；而 “`set logging redirect on`”命令會讓gdb的日志不會打印在終端。 參見[gdb手冊](https://sourceware.org/gdb/onlinedocs/gdb/Logging-Output.html). ## 貢獻者 nanxiao