(Solved) : Identity Crisis Manual Page Unix Lists Acceptable Usage Command Also Lists Whoami Modify W Q44046134 . . .
Identity crisis: The manual page in UNIX for who lists who am ias an acceptable *usage of * the command. It also lists whoami.Modify who2.c so it supports the who am i *usage. Write a C programthat works like whoami.
The who2.c file is:
#include
#include
#include
#include
#include
/* #define SHOWHOST */
void showtime(long);
void show_info(struct utmp *);
int main()
{
struct utmp utbuf; /* read info into here */
int utmpfd; /* read from this descriptor */
if ( (utmpfd = open(UTMP_FILE, O_RDONLY)) == -1 ){
perror(UTMP_FILE);
exit(1);
}
while( read(utmpfd, &utbuf, sizeof(utbuf)) == sizeof(utbuf))
show_info( &utbuf );
close(utmpfd);
return 0;
}
/*
* show info()
* displays the contents of the utmp struct
* in human readable form
* * displays nothing if record has no user name
*/
void show_info( struct utmp *utbufp )
{
if ( utbufp->ut_type != USER_PROCESS )
return;
printf(“%-8.8s”, utbufp->ut_name); /* the logname */
printf(” “); /* a space */
printf(“%-8.8s”, utbufp->ut_line); /* the tty */
printf(” “); /* a space */
showtime( utbufp->ut_time ); /* display time */
#ifdef SHOWHOST
if ( utbufp->ut_host[0] != ‘ ‘ )
printf(” (%s)”, utbufp->ut_host);/* the host */
#endif
printf(“n”); /* newline */
}
void showtime( long timeval )
/*
* displays time in a format fit for human consumption
* uses ctime to build a string then picks parts out of it
* Note: %12.12s prints a string 12 chars wide and LIMITS
* it to 12chars.
*/
{
char *cp; /* to hold address of time */
cp = ctime(&timeval); /* convert time to string */
/* string looks like */
/* Mon Feb 4 00:46:40 EST 1991 */
/* 0123456789012345. */
printf(“%12.12s”, cp+4 ); /* pick 12 chars from pos 4 */
}
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Answer to Identity crisis: The manual page in UNIX for who lists who am i as an acceptable *usage of * the command. It also lists …
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