Commit 057609ee authored by Nicholas De Nova's avatar Nicholas De Nova

Add logname(1).

parent 207f554b
......@@ -25,6 +25,7 @@ help
kernelinfo
kill
ln
logname
ls
memstat
mkdir
......
......@@ -36,6 +36,7 @@ id \
kernelinfo \
kill \
ln \
logname \
ls \
memstat \
mkdir \
......@@ -74,6 +75,7 @@ xinstall
MANPAGES1=\
chkblayout.1 \
kernelinfo.1 \
logname.1 \
memstat.1 \
pager.1 \
passwd.1 \
......
.Dd October 13, 2016
.Dt LOGNAME 1
.Os
.Sh NAME
.Nm logname
.Nd print login name
.Sh SYNOPSIS
.Nm
.Sh DESCRIPTION
.Nm
prints the login name of the session.
.Sh EXIT STATUS
.Nm
will exit with 0 on success and non-zero otherwise.
.Sh SEE ALSO
.Xr id 1 ,
.Xr getlogin 3
/*
* Copyright (c) 2016 Nicholas De Nova.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* logname.c
* Print login name.
*/
#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
static void compact_arguments(int* argc, char*** argv)
{
for ( int i = 0; i < *argc; i++ )
{
while ( i < *argc && !(*argv)[i] )
{
for ( int n = i; n < *argc; n++ )
(*argv)[n] = (*argv)[n+1];
(*argc)--;
}
}
}
int main(int argc, char* argv[])
{
for ( int i = 1; i < argc; i++ )
{
const char* arg = argv[i];
if ( arg[0] != '-' || !arg[1] )
continue;
argv[i] = NULL;
if ( !strcmp(arg, "--") )
break;
if ( arg[1] != '-' )
{
char c;
while ( (c = *++arg) )
switch ( c )
{
default:
errx(1, "unknown option -- '%c'", c);
}
}
else
errx(1, "unknown option: %s", arg);
}
compact_arguments(&argc, &argv);
if ( 1 < argc )
errx(1, "unexpected extra operand");
char* login_name = getlogin();
if ( !login_name )
{
if ( errno )
err(1, "could not get login name");
else
errx(1, "could not get login name");
}
printf("%s\n", login_name);
if ( ferror(stdout) || fflush(stdout) == EOF )
err(1, "stdout");
return 0;
}
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