# 打印程序进程空间信息 ## 例子 a.c: #include <stdio.h> int func(int a, int b) { int c = a * b; printf("c is %d\n", c); } int main(void) { func(1, 2); return 0; } b.c: #include <stdio.h> int func1(int a) { return 2 * a; } int func2(int a) { int c = 0; c = 2 * func1(a); return c; } int func3(int a) { int c = 0; c = 2 * func2(a); return c; } int main(void) { printf("%d\n", func3(10)); return 0; } ## 技巧 使用gdb调试多个进程时，可以使用“`maint info program-spaces`”打印当前所有被调试的进程信息。以上面程序为例： [root@localhost nan]# gdb a GNU gdb (GDB) 7.8.1 ...... Reading symbols from a...done. (gdb) start Temporary breakpoint 1 at 0x4004f9: file a.c, line 10. Starting program: /home/nan/a Temporary breakpoint 1, main () at a.c:10 10 func(1, 2); (gdb) add-inferior -exec b Added inferior 2 Reading symbols from b...done. (gdb) i inferiors b Args must be numbers or '$' variables. (gdb) i inferiors Num Description Executable 2 <null> /home/nan/b * 1 process 15753 /home/nan/a (gdb) inferior 2 [Switching to inferior 2 [<null>] (/home/nan/b)] (gdb) start Temporary breakpoint 2 at 0x4004f9: main. (2 locations) Starting program: /home/nan/b Temporary breakpoint 2, main () at b.c:24 24 printf("%d\n", func3(10)); (gdb) i inferiors Num Description Executable * 2 process 15902 /home/nan/b 1 process 15753 /home/nan/a (gdb) clone-inferior -copies 2 Added inferior 3. Added inferior 4. (gdb) i inferiors Num Description Executable 4 <null> /home/nan/b 3 <null> /home/nan/b * 2 process 15902 /home/nan/b 1 process 15753 /home/nan/a (gdb) maint info program-spaces Id Executable 4 /home/nan/b Bound inferiors: ID 4 (process 0) 3 /home/nan/b Bound inferiors: ID 3 (process 0) * 2 /home/nan/b Bound inferiors: ID 2 (process 15902) 1 /home/nan/a Bound inferiors: ID 1 (process 15753) 可以看到执行“`maint info program-spaces`”命令后，打印出当前有4个`program-spaces`（编号从1到4）。另外还有每个`program-spaces`对应的程序，`inferior`编号及进程号。 参见[gdb手册](https://sourceware.org/gdb/onlinedocs/gdb/Inferiors-and-Programs.html). ## 贡献者 nanxiao