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https://github.com/coreutils/coreutils.git
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135 lines
3.4 KiB
C
135 lines
3.4 KiB
C
/* GNU's read utmp module.
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Copyright (C) 1992-2001 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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/* Written by jla; revised by djm */
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#include <config.h>
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#include <stdio.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#if defined(STDC_HEADERS) || defined(HAVE_STRING_H)
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# include <string.h>
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#else
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# include <strings.h>
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#endif /* STDC_HEADERS || HAVE_STRING_H */
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#include "readutmp.h"
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#include "unlocked-io.h"
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char *xmalloc ();
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char *realloc ();
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/* Copy UT->ut_name into storage obtained from malloc. Then remove any
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trailing spaces from the copy, NUL terminate it, and return the copy. */
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char *
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extract_trimmed_name (const STRUCT_UTMP *ut)
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{
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char *p, *trimmed_name;
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trimmed_name = xmalloc (sizeof (UT_USER (ut)) + 1);
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strncpy (trimmed_name, UT_USER (ut), sizeof (UT_USER (ut)));
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/* Append a trailing space character. Some systems pad names shorter than
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the maximum with spaces, others pad with NULs. Remove any spaces. */
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trimmed_name[sizeof (UT_USER (ut))] = ' ';
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p = strchr (trimmed_name, ' ');
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if (p != NULL)
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*p = '\0';
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return trimmed_name;
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}
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/* Read the utmp entries corresponding to file FILENAME into freshly-
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malloc'd storage, set *UTMP_BUF to that pointer, set *N_ENTRIES to
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the number of entries, and return zero. If there is any error,
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return non-zero and don't modify the parameters. */
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#ifdef UTMP_NAME_FUNCTION
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int
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read_utmp (const char *filename, int *n_entries, STRUCT_UTMP **utmp_buf)
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{
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int n_read;
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STRUCT_UTMP *u;
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STRUCT_UTMP *utmp = NULL;
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/* Ignore the return value for now.
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Solaris' utmpname returns 1 upon success -- which is contrary
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to what the GNU libc version does. In addition, older GNU libc
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versions are actually void. */
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UTMP_NAME_FUNCTION (filename);
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SET_UTMP_ENT ();
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n_read = 0;
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while ((u = GET_UTMP_ENT ()) != NULL)
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{
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++n_read;
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utmp = (STRUCT_UTMP *) realloc (utmp, n_read * sizeof (STRUCT_UTMP));
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if (utmp == NULL)
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return 1;
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utmp[n_read - 1] = *u;
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}
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END_UTMP_ENT ();
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*n_entries = n_read;
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*utmp_buf = utmp;
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return 0;
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}
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#else
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int
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read_utmp (const char *filename, int *n_entries, STRUCT_UTMP **utmp_buf)
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{
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FILE *utmp;
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struct stat file_stats;
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size_t n_read;
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size_t size;
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STRUCT_UTMP *buf;
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utmp = fopen (filename, "r");
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if (utmp == NULL)
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return 1;
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fstat (fileno (utmp), &file_stats);
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size = file_stats.st_size;
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if (size > 0)
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buf = (STRUCT_UTMP *) xmalloc (size);
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else
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{
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fclose (utmp);
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return 1;
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}
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/* Use < instead of != in case the utmp just grew. */
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n_read = fread (buf, 1, size, utmp);
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if (ferror (utmp) || fclose (utmp) == EOF
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|| n_read < size)
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return 1;
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*n_entries = size / sizeof (STRUCT_UTMP);
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*utmp_buf = buf;
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return 0;
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}
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#endif
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