Shell script blog -OR- Give me tips on how to write better scripts!

Question

Hi folks,
I don't write a lot of shell scripts, and the ones that I do write are usually quite short, so as a learning exercise I made a shell/CGI blog script.. And I was hoping that some of the shell scripting experts in the community could give me some pointers on form, style, etc! The script works just fine, but maybe I haven't coded it very elegantly. Or maybe in some places I haven't necessarily used the right (or most appropriate?) commands to accomplish what I want.
It's a simple blog. It can either:
- Display a blog post (by default the newest, unless the name of a post is given)
- Display a listing of posts for a certain tag
Posts are saved in normal files in markdown format. Tagging is accomplished by putting the name of the tag(s) into the filename, separated by hyphens. For example: the file "wonderful_blog_post-whining-computers-archlinux.md" would be a post named "wonderful blog post", and it would have three tags ("whining", "computers", "archlinux"). Maybe it's not the best idea in the world... but I went with it anyhow
I put the script on pastebin for you all to see: http://pastebin.com/L8nMpUjT
Please do take a look and let me know if I've done something badly! Hopefully I can learn a thing or two from your comments.
And there's a working example of it here: http://www.ynnhoj.net/thedump/s.cgi

Answer 1

falconindy wrote:
To sort files by modification time (safely) requires GNU stat and some bash:
declare -a files
while IFS=$'\t' read -r -d '' ts file; do
files+=("$file")
done < <(stat --printf '%Y\t%n\0' * | sort -zn)
printf "%s\n" "${files[@]}"
The array is of course unnecessary as you could print inside the loop, but I see no way around the usage of null delimiters and bashisms (read's -d flag in particular) to be 100% safe.
Thanks for the example, though I'm trying to avoid bash and write my script in posix shell. So after some tinkering, this is what I've come up with to make a simple list of blog post file names:
#!/bin/sh
cd posts
while IFS=$'\t' read -r ts file; do
ALLPOSTS="$ALLPOSTS $file"
done << EOF
$(stat --printf '%Y\t%n\n' *.md | sort -rn)
EOF
echo $ALLPOSTS
So I suppose that it isn't 100% safe - but could it be acceptable? Is there anything else I could do?
Edit: as it turns out, my server is running some flavour of BSD, I think FreeBSD. So the above examples don't work with FreeBSD's stat. Ah well..
Last edited by upsidaisium (2011-02-23 08:26:29)