If I open a Linux shell that uses an apt package management system and execute apt-cache search --names-only "(^man)+" why does it match/output things like:
- gman-X的小人（1）前端
- jed-extra-有用的Jed模式和实用程序的集合
我对POSIX.2正则表达式模式的初步了解认为原子（^ man）只能与行首的字符串“ man”相匹配。显然，上述行在行开始处没有“ man”。为什么将它们打印到我的终端上？
man apt-cachesays--names-onlymeans "Only search on the package and provided package names". Your command will match any package where either the package name or a provided package name starts withman, and bothgmanandjed-extrahaveman-browseras a provided package name (you can see this withapt-cache show).