/usr/share/doc/slsh/examples/utmp.sl is in slsh 2.2.4-15ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 | % This file illustrates how to read a binary file into a structure. In this
% case, the file is the Unix utmp file.
%
% Note that the format of the utmp file will vary with the OS. The format
% encoded here is for glibc Linux, but even that may be version-dependent.
variable format, size, fp, buf;
variable is_glibc = 1;
#ifeval is_glibc
typedef struct
{
ut_type, ut_pid, ut_line, ut_id,
ut_user, ut_host, ut_exit, ut_session, ut_tv, ut_addr
} UTMP_Type;
% The ut_tv is a timeval structure which has the format: l2
% Also the ut_exit field is a struct of h2
format = pad_pack_format ("h i S32 S4 S32 S256 h2 l l2 k4 x20");
#else
typedef struct
{
ut_type, ut_pid, ut_line, ut_id,
ut_time, ut_user, ut_host, ut_addr
} UTMP_Type;
format = pad_pack_format ("h i S12 S2 l S8 S16 l");
#endif
size = sizeof_pack (format);
vmessage ("Sizeof of utmp line: %d bytes", size);
define print_utmp (u)
{
() = fprintf (stdout, "%-16s %-12s %-16s %s\n",
u.ut_user, u.ut_line, u.ut_host,
#ifeval is_glibc
ctime (u.ut_tv[0])
#else
ctime (u.ut_time)
#endif
);
}
variable Utmp_File;
foreach (["/var/run/utmp", "/var/log/utmp"])
{
Utmp_File = ();
fp = fopen (Utmp_File, "rb");
if (fp != NULL)
break;
}
if (fp == NULL) error ("Unable to open utmp file");
() = fprintf (stdout, "%-16s %-12s %-16s %s\n",
"USER", "TTY", "FROM", "LOGIN@");
variable U = @UTMP_Type;
while (size == fread_bytes (&buf, size, fp))
{
set_struct_fields (U, unpack (format, buf));
print_utmp (U);
}
() = fclose (fp);
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