32 lines
660 B
C
32 lines
660 B
C
#include <sys/types.h>
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#include <utmp.h>
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#define NULL 0
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extern long lseek();
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extern int open(), read(), close(), ttyslot();
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char *
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getlogin()
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{
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register me, uf;
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struct utmp ubuf ;
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static char answer[sizeof(ubuf.ut_user)+1] ;
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if((me = ttyslot()) < 0)
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return(NULL);
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if((uf = open(UTMP_FILE, 0)) < 0)
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return(NULL);
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(void) lseek(uf, (long)(me * sizeof(ubuf)), 0);
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if(read(uf, (char*)&ubuf, sizeof(ubuf)) != sizeof(ubuf)) {
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(void) close(uf);
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return(NULL);
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}
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(void) close(uf);
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if(ubuf.ut_user[0] == '\0')
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return(NULL);
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strncpy(&answer[0],&ubuf.ut_user[0],sizeof(ubuf.ut_user)) ;
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answer[sizeof(ubuf.ut_user)] = '\0' ;
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return(&answer[0]);
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}
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