uname For Linux

uname is a special version of uname. Supports -a, -s, -r, -n, -v, -m options.

USAGE: uname [options]

-s Print the kernel name -v Print the kernel version -r Print the kernel release -n Print the network node hostname -m Print the machine hardware name -a Print all of the above

Without options, uname acts like uname -s

#include < unistd.h > #include < sys/utsname.h > #include < stdio.h > #include < stdlib.h > #include < string.h >

void print_usage(void);

int main( int argc, char *argv[] ) { int c; extern char *optarg; extern int optind, optopt; int a_flag = 0, s_flag = 0, n_flag = 0, r_flag = 0, v_flag = 0, m_flag = 0; int errflag=0; char host[256]; struct utsname uts;

if ( gethostname( host, 255 ) != 0 || uname( &uts ) < 0 ) { fprintf( stderr, "Unable to get host informationn" ); exit( 1 ); }

/* if no options, then just print sysname */ if ( argc == 1 ) { s_flag = 1; } else { while ( ( c = getopt( argc, argv, "asnrvm" ) ) != -1 ) { switch ( c ) { case 'a': a_flag = 1; break; case 's': s_flag = 1; break; case 'n': n_flag = 1; break; case 'r': r_flag = 1; break; case 'v': v_flag = 1; break; case 'm': m_flag = 1; break; case '?': errflag++; break; } } }

/* Must have been one or more erroneous options passed - print usage info and exit */ if ( errflag != 0 ) { print_usage(); exit( 1 ); }

char *sysname, *machine, *nodename, *release, *version;

sysname=uts.sysname; machine=uts.machine; nodename=uts.nodename; release=uts.release; version=uts.version;

if ( a_flag == 1 ) { printf( "%s %s %s %s %sn", sysname, nodename, release, version, machine ); } else { char *printstring; /* allocate enough space for all eventualities....*/ printstring = (char *)malloc(strlen(sysname)+ strlen(version)+ strlen(release)+ strlen(nodename)+ strlen(machine)+6); strcpy( printstring , "");

if ( s_flag == 1 ) { strcat( printstring, sysname ); strcat( printstring, " "); } if ( n_flag == 1 ) { strcat( printstring, nodename ); strcat( printstring, " "); } if ( r_flag == 1 ) { strcat( printstring, release ); strcat( printstring, " "); } if ( v_flag == 1 ) { strcat( printstring, version ); strcat( printstring, " "); } if ( m_flag == 1 ) { strcat( printstring, machine ); strcat( printstring, " "); } puts( printstring ); free( printstring ); } return 0; }

void print_usage(void) { char *usage[] = { "uname - (C) 2004 Kevin Waldron", "Distributed under the terms of the GNU General Public Licence", "USAGE:", "uname [options]", " -s Print the kernel name", " -v Print the kernel version", " -r Print the kernel release", " -n Print the network node hostname", " -m Print the machine hardware name", " -a Print all of the above", " ", "Without options, uname acts like uname -s" };

int i = 0; for ( i = 0 ; i < 12 ; i++ ) { printf( "%sn", *(usage+i) ); } }