Get name from PID? - objective-c

Question

I am on OSX Mountain Lion and am trying to retrieve a processes' name using its PID.
The following is the code I am using:
pid_t pid = 10687;
char pathBuffer [PROC_PIDPATHINFO_MAXSIZE] = "";
char nameBuffer [256] = "";
int sizeOfVal = sizeof(nameBuffer);
proc_pidpath(pid, pathBuffer, sizeof(pathBuffer));
proc_name(pid, nameBuffer, sizeof(nameBuffer));
NSLog(#"Path: %s\n Name: %s\n", pathBuffer, nameBuffer);
The code above is able to retrieve the name properly, however it only retrieves the first 15 characters and "ignores" the rest. Note this is not a problem with displaying the name, but with retrieving it. The problem is not with the rest of my application as I am testing the above code in a standalone application. Also note that I tried changing the PID, but regardless of what PID I try the code only retrieves the first 15 characters of the name. Path retrieval works perfectly.
Does anyone have any ideas about what I am doing wrong?

Answer 1

The function looks at the value is the struct proc_bsdshortinfo. It is limited to return a 16 byte string, or 15 readable characters when including the null terminator.
From sys/param.h:
#define MAXCOMLEN 16 /* max command name remembered */
From sys/proc_info.h:
struct proc_bsdshortinfo {
uint32_t pbsi_pid; /* process id */
uint32_t pbsi_ppid; /* process parent id */
uint32_t pbsi_pgid; /* process perp id */
uint32_t pbsi_status; /* p_stat value, SZOMB, SRUN, etc */
char pbsi_comm[MAXCOMLEN]; /* upto 16 characters of process name */
uint32_t pbsi_flags; /* 64bit; emulated etc */
uid_t pbsi_uid; /* current uid on process */
gid_t pbsi_gid; /* current gid on process */
uid_t pbsi_ruid; /* current ruid on process */
gid_t pbsi_rgid; /* current tgid on process */
uid_t pbsi_svuid; /* current svuid on process */
gid_t pbsi_svgid; /* current svgid on process */
uint32_t pbsi_rfu; /* reserved for future use*/
};
EDIT: To get around this, get the last path component:
pid_t pid = 3051;
char pathBuffer [PROC_PIDPATHINFO_MAXSIZE];
proc_pidpath(pid, pathBuffer, sizeof(pathBuffer));
char nameBuffer[256];
int position = strlen(pathBuffer);
while(position >= 0 && pathBuffer[position] != '/')
{
position--;
}
strcpy(nameBuffer, pathBuffer + position + 1);
printf("path: %s\n\nname:%s\n\n", pathBuffer, nameBuffer);