我在 ubuntu 18.04 上，遇到了一个奇怪的情况：在执行sudo apt-get purge pcscdand后sudo apt-get purge libpcsclite1：
john@home:~/$ sudo apt-get purge pcscd
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
pcscd*
0 upgraded, 0 newly installed, 1 to remove and 167 not upgraded.
1 not fully installed or removed.
After this operation, 175 kB disk space will be freed.
Do you want to continue? [Y/n] Y
(Reading database ... 190938 files and directories currently installed.)
Removing pcscd (1.8.26-3) ...
Processing triggers for man-db (2.8.3-2ubuntu0.1) ...
(Reading database ... 190928 files and directories currently installed.)
Purging configuration files for pcscd (1.8.26-3) ...
Processing triggers for ureadahead (0.100.0-21) ...
Processing triggers for systemd (237-3ubuntu10.38) ...
进而：
john@home:~/$ sudo apt-get purge libpcsclite1
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
fonts-dejavu-extra java-common libatk-wrapper-java libatk-wrapper-java-jni libgif7
Use 'sudo apt autoremove' to remove them.
The following additional packages will be installed:
gnome-control-center-data libnm0 libnma0
The following packages will be REMOVED:
ca-certificates-java* default-jre* default-jre-headless* gnome-control-center* libpcsclite-dev* libpcsclite1* network-manager*
network-manager-config-connectivity-ubuntu* network-manager-gnome* network-manager-pptp* network-manager-pptp-gnome*
openjdk-11-jre* openjdk-11-jre-headless* openjdk-8-jre* openjdk-8-jre-headless* ubuntu-desktop* wpasupplicant*
The following packages will be upgraded:
gnome-control-center-data libnm0 libnma0
3 upgraded, 0 newly installed, 17 to remove and 158 not upgraded.
Need to get 886 kB of archives.
After this operation, 293 MB disk space will be freed.
Do you want to continue? [Y/n] Y
Get:1 http://jp.archive.ubuntu.com/ubuntu bionic-updates/main amd64 gnome-control-center-data all 1:3.28.2-0ubuntu0.18.04.6 [507 kB]
Get:2 http://jp.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libnm0 amd64 1.10.6-2ubuntu1.4 [298 kB]
Get:3 http://jp.archive.ubuntu.com/ubuntu bionic-updates/main amd64 libnma0 amd64 1.8.10-2ubuntu3 [80.4 kB]
Fetched 886 kB in 0s (3,392 kB/s)
(Reading database ... 190927 files and directories currently installed.)
Removing openjdk-8-jre:amd64 (8u275-b01-0ubuntu1~18.04) ...
Removing default-jre (2:1.11-68ubuntu1~18.04.1) ...
Removing openjdk-11-jre:amd64 (11.0.9.1+1-0ubuntu1~18.04) ...
Removing openjdk-8-jre-headless:amd64 (8u275-b01-0ubuntu1~18.04) ...
update-alternatives: removing manually selected alternative - switching java to auto mode
update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/java to provide /usr/bin/java (java) in auto mode
Removing default-jre-headless (2:1.11-68ubuntu1~18.04.1) ...
Removing ubuntu-desktop (1.417.3) ...
Removing gnome-control-center (1:3.28.2-0ubuntu0.18.04.4) ...
Removing libpcsclite-dev (1.8.23-1) ...
Removing network-manager-gnome (1.8.10-2ubuntu2) ...
Removing network-manager-config-connectivity-ubuntu (1.10.6-2ubuntu1.1) ...
Removing network-manager-pptp-gnome (1.2.6-1) ...
Removing network-manager-pptp (1.2.6-1) ...
Removing network-manager (1.10.6-2ubuntu1.1) ...
Removing wpasupplicant (2:2.6-15ubuntu2.5) ...
Removing ca-certificates-java (20180516ubuntu1~18.04.1) ...
Removing openjdk-11-jre-headless:amd64 (11.0.9.1+1-0ubuntu1~18.04) ...
Removing libpcsclite1:amd64 (1.8.23-1) ...
(Reading database ... 190057 files and directories currently installed.)
Preparing to unpack .../gnome-control-center-data_1%3a3.28.2-0ubuntu0.18.04.6_all.deb ...
Unpacking gnome-control-center-data (1:3.28.2-0ubuntu0.18.04.6) over (1:3.28.2-0ubuntu0.18.04.4) ...
Preparing to unpack .../libnm0_1.10.6-2ubuntu1.4_amd64.deb ...
Unpacking libnm0:amd64 (1.10.6-2ubuntu1.4) over (1.10.6-2ubuntu1.1) ...
Preparing to unpack .../libnma0_1.8.10-2ubuntu3_amd64.deb ...
Unpacking libnma0:amd64 (1.8.10-2ubuntu3) over (1.8.10-2ubuntu2) ...
Processing triggers for mime-support (3.60ubuntu1) ...
Processing triggers for desktop-file-utils (0.23-1ubuntu3.18.04.2) ...
Setting up libnm0:amd64 (1.10.6-2ubuntu1.4) ...
Processing triggers for libglib2.0-0:amd64 (2.56.4-0ubuntu0.18.04.6) ...
No such key 'Gtk/IMModule' in schema 'org.gnome.settings-daemon.plugins.xsettings' as specified in override file '/usr/share/glib-2.0/schemas/50_sogoupinyin.gschema.override'; ignoring override for this key.
Setting up gnome-control-center-data (1:3.28.2-0ubuntu0.18.04.6) ...
Processing triggers for libc-bin (2.27-3ubuntu1.2) ...
Processing triggers for man-db (2.8.3-2ubuntu0.1) ...
Processing triggers for gnome-menus (3.13.3-11ubuntu1.1) ...
Setting up libnma0:amd64 (1.8.10-2ubuntu3) ...
Processing triggers for dbus (1.12.2-1ubuntu1.2) ...
Processing triggers for ca-certificates (20201027ubuntu0.18.04.1) ...
Updating certificates in /etc/ssl/certs...
0 added, 0 removed; done.
Running hooks in /etc/ca-certificates/update.d...
updates of cacerts keystore disabled.
done.
Processing triggers for hicolor-icon-theme (0.17-2) ...
(Reading database ... 190056 files and directories currently installed.)
Purging configuration files for ca-certificates-java (20180516ubuntu1~18.04.1) ...
Purging configuration files for network-manager-pptp (1.2.6-1) ...
Purging configuration files for network-manager-gnome (1.8.10-2ubuntu2) ...
Purging configuration files for wpasupplicant (2:2.6-15ubuntu2.5) ...
Purging configuration files for openjdk-11-jre-headless:amd64 (11.0.9.1+1-0ubuntu1~18.04) ...
Purging configuration files for network-manager (1.10.6-2ubuntu1.1) ...
dpkg: warning: while removing network-manager, directory '/etc/NetworkManager/system-connections' not empty so not removed
Purging configuration files for openjdk-8-jre-headless:amd64 (8u275-b01-0ubuntu1~18.04) ...
Processing triggers for ureadahead (0.100.0-21) ...
Processing triggers for libc-bin (2.27-3ubuntu1.2) ...
Processing triggers for systemd (237-3ubuntu10.38) ...
Processing triggers for dbus (1.12.2-1ubuntu1.2) ...
john@home:~/$
然后我尝试从下载的文件中安装特定版本的两个包.deb：
john@home:~/$ sudo dpkg -i 1804/libpcsclite1_1.8.26-3_amd64.deb 1804/pcscd_1.8.26-3_amd64.deb
Selecting previously unselected package libpcsclite1:amd64.
(Reading database ... 189980 files and directories currently installed.)
Preparing to unpack .../libpcsclite1_1.8.26-3_amd64.deb ...
Unpacking libpcsclite1:amd64 (1.8.26-3) ...
Selecting previously unselected package pcscd.
Preparing to unpack 1804/pcscd_1.8.26-3_amd64.deb ...
Unpacking pcscd (1.8.26-3) ...
Setting up libpcsclite1:amd64 (1.8.26-3) ...
Setting up pcscd (1.8.26-3) ...
Created symlink /etc/systemd/system/sockets.target.wants/pcscd.socket → /lib/systemd/system/pcscd.socket.
Processing triggers for libc-bin (2.27-3ubuntu1.2) ...
Processing triggers for systemd (237-3ubuntu10.38) ...
Processing triggers for ureadahead (0.100.0-21) ...
Processing triggers for man-db (2.8.3-2ubuntu0.1) ...
john@home:~/$
之后我重新启动电脑，就再也检测不到网卡了。
发生了什么？？计算机的网络接口pcscd与libpcsclite1计算机的网络接口有何关系？如何修复它？
答案1
看来 wpasupplicant 至少取决于是否安装了 libpcsclite1，因此当您删除 libpcsclite1 时，它还会删除 wpasupplicant 和一堆其他与网络相关的软件包。
我建议重新安装所有已删除的软件包（任何以“Removing”开头的行）sudo apt-get purge libpcsclite1。