在 Ubuntu 14.04 上，我尝试做一个蓝牙设备列表的小示例，但在编译这个简约演示时，我遇到了一个关于与蓝牙共享库链接的简单问题http://people.csail.mit.edu/albert/bluez-intro/c404.html http://people.csail.mit.edu/albert/bluez-intro/c404.html:
$ sudo apt-get install libbluetooth-dev
$ gcc -lbluetooth simplescan.c -o simplescan
/tmp/ccuwRsB5.o: In function `main':
simplescan.c:(.text+0x79): undefined reference to `hci_get_route'
simplescan.c:(.text+0x8c): undefined reference to `hci_open_dev'
simplescan.c:(.text+0x132): undefined reference to `hci_inquiry'
simplescan.c:(.text+0x18f): undefined reference to `ba2str'
simplescan.c:(.text+0x1f0): undefined reference to `hci_read_remote_name'
collect2: error: ld returned 1 exit status
$ nm -D /usr/lib/x86_64-linux-gnu/libbluetooth.so.3.13.0 | grep hci_get_route
0000000000008f00 T hci_get_route
蓝牙共享库似乎已找到并包含所需的功能，但链接阶段未实现。
解决方案令我惊讶：给予 gcc 的参数顺序很重要。 “-lbluetooth”应该放在“simplescan.c”之后：
$ gcc simplescan.c -lbluetooth -o simplescan # Success
$ gcc -lbluetooth simplescan.c -o simplescan # Failure
/tmp/ccWhZFXs.o: In function `main':
simplescan.c:(.text+0x79): undefined reference to `hci_get_route'
simplescan.c:(.text+0x8c): undefined reference to `hci_open_dev'
simplescan.c:(.text+0x132): undefined reference to `hci_inquiry'
simplescan.c:(.text+0x18f): undefined reference to `ba2str'
simplescan.c:(.text+0x1f0): undefined reference to `hci_read_remote_name'
collect2: error: ld returned 1 exit status
本文内容由网友自发贡献，版权归原作者所有，本站不承担相应法律责任。如您发现有涉嫌抄袭侵权的内容，请联系:hwhale#tublm.com(使用前将#替换为@)
