93 lines
2.7 KiB
C
93 lines
2.7 KiB
C
/* Get a host configuration item kept as the whole contents of a file.
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Copyright (C) 1996-2015 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library 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 GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <fcntl.h>
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#include <hurd.h>
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#include <hurd/lookup.h>
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#include "hurdhost.h"
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#include <string.h>
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ssize_t
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_hurd_get_host_config (const char *item, char *buf, size_t buflen)
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{
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error_t err;
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char *data;
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mach_msg_type_number_t nread, more;
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file_t config;
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err = __hurd_file_name_lookup (&_hurd_ports_use, &__getdport, 0,
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item, O_RDONLY, 0, &config);
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switch (err)
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{
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case 0: /* Success; read file contents below. */
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break;
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case ENOENT: /* ? Others? All errors? */
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/* The file does not exist, so no value has been set. Rather than
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causing gethostname et al to fail with ENOENT, give an empty value
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as other systems do before sethostname has been called. */
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if (buflen != 0)
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*buf = '\0';
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return 0;
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default:
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return __hurd_fail (err);
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}
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data = buf;
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nread = buflen;
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err = __io_read (config, &data, &nread, -1, buflen);
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if (! err)
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/* Check if there is more in the file we didn't read. */
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err = __io_readable (config, &more);
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__mach_port_deallocate (__mach_task_self (), config);
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if (err)
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return __hurd_fail (err);
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if (data != buf)
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{
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memcpy (buf, data, nread);
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__vm_deallocate (__mach_task_self (), (vm_address_t) data, nread);
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}
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/* If the file is empty, give an empty value. */
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if (nread == 0)
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{
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if (buflen != 0)
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*buf = '\0';
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return 0;
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}
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/* Remove newlines in case someone wrote the file by hand. */
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while (nread > 0 && buf[nread - 1] == '\n')
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buf[--nread] = '\0';
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/* Null-terminate the result if there is enough space. */
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if (nread < buflen)
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buf[nread] = '\0';
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else
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if (buf[nread - 1] != '\0')
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more = 1;
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if (more)
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/* If we didn't read the whole file, tell the caller to use a bigger
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buffer next time. */
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return __hurd_fail (ENAMETOOLONG);
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return nread;
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}
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