74 lines
1.4 KiB
C
Executable File
74 lines
1.4 KiB
C
Executable File
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
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/* All Rights Reserved */
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/* THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T */
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/* The copyright notice above does not evidence any */
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/* actual or intended publication of such source code. */
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#ident "@(#)uid.c 1.5 92/07/14 SMI" /* SVr4.0 1.5 */
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#include <sys/types.h>
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#include <stdio.h>
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#include <userdefs.h>
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#include <sys/param.h>
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#ifndef MAXUID
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#include <limits.h>
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#ifdef UID_MAX
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#define MAXUID UID_MAX
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#else
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#define MAXUID 60000
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#endif
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#endif
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extern pid_t getpid();
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static char cmdbuf[ 128 ];
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uid_t
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findnextuid()
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{
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FILE *fptr;
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uid_t last, next;
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/*
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Sort the used UIDs in decreasing order to return
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MAXUSED + 1
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*/
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if ( (fptr=popen(
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"exec sh -c \"getent passwd|cut -f3 -d:|sort -nr|uniq\" 2>/dev/null",
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"r")) == NULL)
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return( -1 );
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if( fscanf( fptr, "%ld\n", &next ) == EOF ) {
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pclose( fptr);
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return( DEFRID + 1 );
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}
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/* Still some UIDs left between next and MAXUID */
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if( next < MAXUID ) {
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pclose(fptr);
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return( next <= DEFRID? DEFRID + 1: next + 1 );
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}
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/* Look for the next unused one */
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for( last = next; fscanf( fptr, "%ld\n", &next ) != EOF; last = next ) {
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if( next <= DEFRID ) {
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pclose(fptr);
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if( last != DEFRID + 1 )
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return( DEFRID + 1 );
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else
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return( -1 );
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}
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if( (last != (next + 1)) && ((next + 1) < MAXUID) ) {
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pclose(fptr);
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return( next + 1 );
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}
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}
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pclose(fptr);
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/* None left */
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return( -1 );
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}
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