54 lines
1.5 KiB
C
54 lines
1.5 KiB
C
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/*
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* libudev - interface to udev device information
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*
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* Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
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*
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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 of the License, or
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* (at your option) any later version.
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*
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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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*
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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, see <http://www.gnu.org/licenses/>.
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*/
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#include "config.h"
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#include <stdio.h>
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#include <stdlib.h>
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#include <stddef.h>
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#include <unistd.h>
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#include <errno.h>
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#include <string.h>
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#include <dirent.h>
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#include <sys/stat.h>
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#include "libudev.h"
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#include "libudev-private.h"
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#include "../udev.h"
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ssize_t util_get_sys_subsystem(struct udev *udev, const char *devpath, char *subsystem, size_t size)
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{
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char path[PATH_SIZE];
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ssize_t len;
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const char *pos;
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strlcpy(path, udev_get_sys_path(udev), sizeof(path));
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strlcat(path, devpath, sizeof(path));
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strlcat(path, "/subsystem", sizeof(path));
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len = readlink(path, path, sizeof(path));
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if (len < 0 || len >= (ssize_t) sizeof(path))
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return -1;
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path[len] = '\0';
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pos = strrchr(path, '/');
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if (pos == NULL)
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return -1;
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pos = &pos[1];
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return strlcpy(subsystem, pos, size);
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}
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