在我昨天更新以下軟體包後debian wheezy，tr命令停止工作。

Start-Date: 2016-02-16  23:10:06
Commandline: apt-get dist-upgrade
Upgrade: libkrb5-3:amd64 (1.10.1+dfsg-5+deb7u6, 1.10.1+dfsg-5+deb7u7),
libk5crypto3:amd64 (1.10.1+dfsg-5+deb7u6, 1.10.1+dfsg-5+deb7u7),
libgraphite2-2.0.0:amd64 (1.1.3-1, 1.3.5-1~deb7u1),
libc-bin:amd64 (2.13-38+deb7u8, 2.13-38+deb7u10),
libc6-i386:amd64 (2.13-38+deb7u8, 2.13-38+deb7u10),
libgssrpc4:amd64 (1.10.1+dfsg-5+deb7u6, 1.10.1+dfsg-5+deb7u7),
iceweasel-l10n-de:amd64 (38.6.0esr-1~deb7u1, 38.6.1esr-1~deb7u1),
locales:amd64 (2.13-38+deb7u8, 2.13-38+deb7u10),
iceweasel:amd64 (38.6.0esr-1~deb7u1, 38.6.1esr-1~deb7u1),
libkrb5support0:amd64 (1.10.1+dfsg-5+deb7u6, 1.10.1+dfsg-5+deb7u7),
multiarch-support:amd64 (2.13-38+deb7u8, 2.13-38+deb7u10),
libgcrypt11:amd64 (1.5.0-5+deb7u3, 1.5.0-5+deb7u4),
libkadm5clnt-mit8:amd64 (1.10.1+dfsg-5+deb7u6, 1.10.1+dfsg-5+deb7u7),
libkadm5srv-mit8:amd64 (1.10.1+dfsg-5+deb7u6, 1.10.1+dfsg-5+deb7u7),
libc6-dev:amd64 (2.13-38+deb7u8, 2.13-38+deb7u10),
krb5-locales:amd64 (1.10.1+dfsg-5+deb7u6, 1.10.1+dfsg-5+deb7u7),
libkdb5-6:amd64 (1.10.1+dfsg-5+deb7u6, 1.10.1+dfsg-5+deb7u7),
libgssapi-krb5-2:amd64 (1.10.1+dfsg-5+deb7u6, 1.10.1+dfsg-5+deb7u7),
libc-dev-bin:amd64 (2.13-38+deb7u8, 2.13-38+deb7u10),
libc6:amd64 (2.13-38+deb7u8, 2.13-38+deb7u10),
libc6-dev-i386:amd64 (2.13-38+deb7u8, 2.13-38+deb7u10)
End-Date: 2016-02-16  23:10:28

輸出範例

> echo abcdefgh | tr -d [:alnum:]
bcdefgh

> echo abcdefgh | tr -Cd [:alnum:]
a

> type tr
tr is /usr/bin/tr

你有一個名為 的文件a嗎？

$ echo [:alnum:]

$ touch a
$ echo [:alnum:]
a

引用你的字元串。

$ echo '[:alnum:]' | tr -d '[:alnum:]'
[::]

引用自：https://unix.stackexchange.com/questions/263894