我去，environ变量太诡异了，gdb看不到？
c environ c++ gdb
[解决办法]
你可以间接引用:
引用:能打印的话，说明environ就是这个值：
(gdb) p environ
$1 = (char **) 0x0
否则GDB会提示找不到这样的符号。
可以肯定不是NULL，environ变量在linux下是在argv变量之后的，你可以访问environ[0]试试，
如果是NULL的话，肯定core dump了
(gdb……
[解决办法]
对学习编程者的忠告：
眼过千遍不如手过一遍！
书看千行不如手敲一行！
手敲千行不如单步一行！
单步源代码千行不如单步对应汇编一行！
layout regs：显示源代码/反汇编和CPU寄存器窗口
[解决办法]
C:\Program Files\Microsoft Visual Studio\VC98\CRT\SRC\STDENVP.C
40: /***
41: *_setenvp - set up "envp" for C programs
42: *
43: *Purpose:
44: * Reads the environment and build the envp array for C programs.
45: *
46: *Entry:
47: * The environment strings occur at _aenvptr.
48: * The list of environment strings is terminated by an extra null
49: * byte. Thus two null bytes in a row indicate the end of the
50: * last environment string and the end of the environment, resp.
51: *
52: *Exit:
53: * "environ" points to a null-terminated list of pointers to ASCIZ
54: * strings, each of which is of the form "VAR=VALUE". The strings
55: * are copied from the environment area. This array of pointers will
56: * be malloc'ed. The block pointed to by _aenvptr is deallocated.
57: *
58: *Uses:
59: * Allocates space on the heap for the environment pointers.
60: *
61: *Exceptions:
62: * If space cannot be allocated, program is terminated.
63: *
64: *******************************************************************************/
[解决办法]
Access to specific environment variables is normally through the getenv and putenv functions,