How to customize word definition in vim?

Question

Suppose that i am editing a line such as below(just a bash command),my cursor is locating at the monitor's m:

1.How can quickly move cursor at the alsa's a?

ffmpeg -f pulse -i  alsa_output.pci-0000_09_00.6.analog-stereo.monitor  music.mp3

2.How can quickly copy the string alsa_output.pci-0000_09_00.6.analog-stereo.monitor?
A word is a string which begins with a space and end with a space.How can?
If i can define such string alsa_output.pci-0000_09_00.6.analog-stereo.monitor as a word, press b and yiw can do the trick.

Answer 1

The iskeyword setting controls which charters are part of a "word"; you can add the . and - to it (isk being the abbreviated form):

:setl isk+=- isk+=.

And then b will go back to the "word" as you want.

This affects many things though, including things like expand('<cword>') that may be used by plugin, syntax highlighting for some filetypes, commands like *, and many more. Personally I found setting iskeyword more trouble than it's worth in almost all cases, also because having commands behave different in different filetypes is confusing.

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Instead, I would use F<Space> or T<Space> in your example, F ("find") will find a character backwards, moving to it, and T ("'till") will do the same, but puts the cursor one character before it. f and t do the same, but search forward. T is clearly the better choice here.

To copy that entire string, you can use T<Space>yt<Space>.