3.6.     81

.    NULL-.   [ ] 
   :

char *const [] = {"traverse",".", ">","1000",NULL};

    :

execv("traverse", ) ;

    traverse      ,
   1000 .

 int execve(const char *path,char *const arg[],
char *const envp[]) ;

    execv (),   :   -
 , envp [ ],   .

 int execvp(const char *?ile,char *const arg [ ] ) ;

 file   .   -
   (   ),  -
  ,      
 .     .   -
 NULL-.

     execv ()   :

char *const arg[] = {"traverse",".", ">","1000".NULL};

char *const envp[] = {"files=50".NULL};

execv("/path/traverse",arg) ;

execve("/path/traverse",arg,envp) ;

execvp("traverse",arg) ;

     execv-   -
  traverse.

3.6.3.3.      ()

     argv [ ]   envp [ ], -
   .     -
         -
 (   envp [ ])   
sysconf ().     ,   name 
  _SC_ARG_MAX.



#include <unistd.h>
long sysconf(int name);

         
,    ,   
  ,     .
  sysconf ()   ,   name  -
  _SC_CHILD_MAX.