hpr2045 :: Some other Bash tips
Yet more information about types of expansion in Bash
Hosted by Dave Morriss on Friday 2016-06-03 is flagged as Explicit and is released under a CC-BY-SA license.
Tags: Bash,expansion,process substitution, word splitting.
Listen in ogg, spx, or mp3 format. | Comments (0)
Part of the series: Bash Scripting
This is an open series in which Hacker Public Radio Listeners can share their Bash scripting knowledge and experience with the community. General programming topics and Bash commands are explored along with some tutorials for the complete novice.
Some other Bash tips
As we saw in the last episode 1951 (and others in this sub-series) there are eight types of expansion applied to the command line in the following order:
- Brace expansion (we looked at this subject in episode 1884)
- Tilde expansion (seen in episode 1903)
- Parameter and variable expansion (this was covered in episode 1648)
- Command substitution (seen in episode 1903)
- Arithmetic expansion (seen in episode 1951)
- Process substitution
- Word splitting
- Pathname expansion
We will look at process substitution and word splitting in this episode but since there is a lot to cover in these subjects, we'll save pathname expansion for the next episode.
I have written out a moderately long set of notes about this subject and these are available here https://hackerpublicradio.org/eps/hpr2045/full_shownotes.html.
- HPR episode 1648 "Bash parameter manipulation": https://hackerpublicradio.org/eps.php?id=1648
- HPR episode 1843 "Some Bash tips": https://hackerpublicradio.org/eps.php?id=1843
- HPR episode 1884 "Some more Bash tips": https://hackerpublicradio.org/eps.php?id=1884
- HPR episode 1903 "Some further Bash tips": https://hackerpublicradio.org/eps.php?id=1903
- HPR episode 1951 "Some additional Bash tips": https://hackerpublicradio.org/eps.php?id=1951
- "Introduction to sed" series on HPR:
- Wikipedia article on the "Named pipe": https://en.wikipedia.org/wiki/Named_pipe
- Wikipedia article on the "IFS" variable: https://en.wikipedia.org/wiki/Internal_field_separator
- Advanced Bash-Scripting Guide: Section 9.1 Bash Internal Variables (including
Automatically generated using whisper
whisper --model tiny --language en hpr2045.wav