Zsh Mailing List Archive
Messages sorted by: Reverse Date, Date, Thread, Author

Linux 2.5 and Zsh bug

When running zsh on a Linux 2.5 kernel, the prompt always has a hash sign '#' rather than the normal user '$'. This probably happens because the shell function privasserted() is returning true for all users. I know nothing about Posix capabilities but the zsh code for this looks suspicious.

Code in question:
/* isolate zsh bug */
#include <stdio.h>
#include <sys/capability.h>

   if(!geteuid()) {
       printf("geteuid() is root\n");
       return 1;
   else  {
       cap_t caps = cap_get_proc();
       if(caps) {
           printf("caps = %p\n", caps);
           /* POSIX doesn't define a way to test whether a capability set *
* is empty or not. Typical. I hope this is conforming... */
           cap_flag_value_t val;
           cap_value_t n;

           for(n = 0; !cap_get_flag(caps, n, CAP_EFFECTIVE, &val); n++) {
               if(val) {
                   printf("capability %#x is %d\n", n, val);
cap_free(caps); /* missing in original zsh code memory leak */
                   return 1;
           printf("last capability %#x\n", n);

   return 0;

int main(int argc, const char **argv) {
   printf("%s privledged\n", privasserted() ?  "Is" : "Not");

On 2.4.18
caps = 0x8049844
last capability 0x1d
Not privledged

On 2.5.43
caps = 0x804a00c
capability 0 is 1
Is privledged

Messages sorted by: Reverse Date, Date, Thread, Author