diff options
Diffstat (limited to 'gnulib/lib/readutmp.c')
m--------- | gnulib | 0 | ||||
-rw-r--r-- | gnulib/lib/readutmp.c | 161 |
2 files changed, 161 insertions, 0 deletions
diff --git a/gnulib b/gnulib deleted file mode 160000 -Subproject 443bc5ffcf7429e557f4a371b0661abe98ddbc1 diff --git a/gnulib/lib/readutmp.c b/gnulib/lib/readutmp.c new file mode 100644 index 0000000..38453eb --- /dev/null +++ b/gnulib/lib/readutmp.c @@ -0,0 +1,161 @@ +/* GNU's read utmp module. + + Copyright (C) 1992-2001, 2003-2006, 2009-2011 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +/* Written by jla; revised by djm */ + +#include <config.h> + +#include "readutmp.h" + +#include <errno.h> +#include <stdio.h> + +#include <sys/types.h> +#include <sys/stat.h> +#include <signal.h> +#include <stdbool.h> +#include <string.h> +#include <stdlib.h> +#include <stdint.h> + +#include "xalloc.h" + +#if USE_UNLOCKED_IO +# include "unlocked-io.h" +#endif + +/* Copy UT->ut_name into storage obtained from malloc. Then remove any + trailing spaces from the copy, NUL terminate it, and return the copy. */ + +char * +extract_trimmed_name (const STRUCT_UTMP *ut) +{ + char *p, *trimmed_name; + + trimmed_name = xmalloc (sizeof (UT_USER (ut)) + 1); + strncpy (trimmed_name, UT_USER (ut), sizeof (UT_USER (ut))); + /* Append a trailing NUL. Some systems pad names shorter than the + maximum with spaces, others pad with NULs. Remove any trailing + spaces. */ + trimmed_name[sizeof (UT_USER (ut))] = '\0'; + for (p = trimmed_name + strlen (trimmed_name); + trimmed_name < p && p[-1] == ' '; + *--p = '\0') + continue; + return trimmed_name; +} + +/* Is the utmp entry U desired by the user who asked for OPTIONS? */ + +static inline bool +desirable_utmp_entry (STRUCT_UTMP const *u, int options) +{ + bool user_proc = IS_USER_PROCESS (u); + if ((options & READ_UTMP_USER_PROCESS) && !user_proc) + return false; + if ((options & READ_UTMP_CHECK_PIDS) + && user_proc + && (UT_PID (u) <= 0 + || (kill (UT_PID (u), 0) < 0 && errno == ESRCH))) + return false; + return true; +} + +/* Read the utmp entries corresponding to file FILE into freshly- + malloc'd storage, set *UTMP_BUF to that pointer, set *N_ENTRIES to + the number of entries, and return zero. If there is any error, + return -1, setting errno, and don't modify the parameters. + If OPTIONS & READ_UTMP_CHECK_PIDS is nonzero, omit entries whose + process-IDs do not currently exist. */ + +#ifdef UTMP_NAME_FUNCTION + +int +read_utmp (char const *file, size_t *n_entries, STRUCT_UTMP **utmp_buf, + int options) +{ + size_t n_read = 0; + size_t n_alloc = 0; + STRUCT_UTMP *utmp = NULL; + STRUCT_UTMP *u; + + /* Ignore the return value for now. + Solaris' utmpname returns 1 upon success -- which is contrary + to what the GNU libc version does. In addition, older GNU libc + versions are actually void. */ + UTMP_NAME_FUNCTION (file); + + SET_UTMP_ENT (); + + while ((u = GET_UTMP_ENT ()) != NULL) + if (desirable_utmp_entry (u, options)) + { + if (n_read == n_alloc) + utmp = x2nrealloc (utmp, &n_alloc, sizeof *utmp); + + utmp[n_read++] = *u; + } + + END_UTMP_ENT (); + + *n_entries = n_read; + *utmp_buf = utmp; + + return 0; +} + +#else + +int +read_utmp (char const *file, size_t *n_entries, STRUCT_UTMP **utmp_buf, + int options) +{ + size_t n_read = 0; + size_t n_alloc = 0; + STRUCT_UTMP *utmp = NULL; + int saved_errno; + FILE *f = fopen (file, "r"); + + if (! f) + return -1; + + for (;;) + { + if (n_read == n_alloc) + utmp = x2nrealloc (utmp, &n_alloc, sizeof *utmp); + if (fread (&utmp[n_read], sizeof utmp[n_read], 1, f) == 0) + break; + n_read += desirable_utmp_entry (&utmp[n_read], options); + } + + saved_errno = ferror (f) ? errno : 0; + if (fclose (f) != 0) + saved_errno = errno; + if (saved_errno != 0) + { + free (utmp); + errno = saved_errno; + return -1; + } + + *n_entries = n_read; + *utmp_buf = utmp; + + return 0; +} + +#endif |