capng_get_rootid - Linux

Overview

The capng_get_rootid command retrieves the effective root user ID for the given capability set. It is primarily used in Linux kernel modules and security-related applications to check the root privileges of a process.

Syntax

int capng_get_rootid(capng_set_t caps)

Options/Flags

None

Examples

To get the effective root user ID of the current process:

#include <cap-ng.h>

int main() {
  capng_set_t caps;
  if (capng_get_caps(&caps) < 0) {
    perror("capng_get_caps");
    return 1;
  }
  uid_t rootid = capng_get_rootid(caps);
  printf("Effective root user ID: %u\n", rootid);
  return 0;
}

Common Issues

  • uid_t overflow: The effective root user ID is returned as a uid_t type, which may overflow on 32-bit systems. Ensure that you handle this case appropriately.

Integration

capng_get_rootid can be used with other capability-related commands, such as capng_set_caps and capng_clear, to manage process capabilities dynamically.

Related Commands