New answers tagged bash
1
I merge my previous code with hints provided by @Oh My Goodness.
I excluded the variable clr_dir. The code thanks to is much more readable.
And I moved temp dir to the same filesystem as is final destination of new CRL.
#!/usr/bin/env bash
set -euo pipefail
cd /etc/pki/tls/misc
crls=(RootCA IntermediateCA IntermediateCA2)
crl_temp=$(mktemp -p .)
for ...
6
for crl in ${crls[@]}; do
It's a good habit to always double-quote array expansions.
Cleaning up the temp directory after a successful run would be a nice touch (or do away with it altogether; see below).
cat ${crl_temp}/*.pem > ${crl_temp}/${new_crl}
mv ${crl_temp}/${new_crl} ${crl_dir}/${new_crl}
I assume you're doing this to get atomic replacement? ...
5
bash is slow to append and index into strings: both operations are \$O(n)\$. Your approach does as many indexes and appends as there are digits in the input, making it \$O(n^2)\$. And processing a string by chomping the first character repeatedly will be \$O(n^2)\$ in almost every language.
Have a look at these timings for large inputs, using your code:
...
3
With this code and your example data, both a/c/0.png and b/0.png get renamed to 1_0.png. This happens because changes to $n inside ( ) get lost when you leave the subshell.
Use bash's "globstar" feature to recurse for you, and assign numbers as normal. **/ matches all subdirectories. You want the current directory too, so add . to the list.
This doesn't ...
4
Limit globbing to directories only by appending a slash: for dir in */
If you cd into subdirectories, you don't need to construct a new path for each file. If you cd inside a subshell with ( cd … ), the original directory will be restored when subshell exits. Make sure to increment n outside of the subshell, or the new value will be lost!
The IFS= is ...
0
Note: a module is actually a directory located in some "wp-content/plugins" directories.
Study case
Your shell command is incorrect, inefficient and unnecessarily convoluted.
for i in $(find . -type d -name 'plugins' | grep 'wp-content/plugins$'); do
find $i -maxdepth 1 -type d -exec sh -c 'for f do basename -- "$f"; done' sh {} + ;
done | sort -u
The ...
1
Variables don't interpolate inside single quotes. You need double quotes.
No need to capture the old version that we're throwing away. The /g is redundant since the pattern can never match more than once per line (being anchored to start-of-line).
What happens with Version: 0.9a? Version:1? Version:? Better to take the whole line, possibly excluding ...
3
If plugins only contain directories, list every unique entry in plugins:
shopt -s extglob
\ls -- **/wp-content/plugins |sort -u
Otherwise, include the final targets in the glob, plus a trailing slash to limit globbing to directories.
That will yield paths relative to ., with trailing slash like siteA/wp-content/plugins/anotherplugin/. We clean it up ...
1
Just maybe rsync for remote synchronisation might be attractive.
rsync --dryrun ...
0
I don't think you need the temporary file, if you open for append (i.e. >>), and use comm to find the non-duplicate lines (after sorting).
4
There's nothing here that requires Bash rather than standard (POSIX) shell, so we can use
#!/bin/sh
However, don't do that, because we can use a Bash feature to avoid exposing the plaintext password to other users (see below).
I recommend making the shell exit if we attempt to expand any unset variables, or if any of the programs we run exits with an ...
3
Try to avoid using echo in your bash script; use printf instead (why? look here):
hashed=$(printf "%s" "$GUAC_PASSWORD" | sha256sum | cut -f1 -d\ )
Note also the uppercase variable in bash script are for environment variables; use lowercase ones (ref).
At last, do not use <<< in your case because it adds a newline and won't output the same hash ...
6
If GUAC_PASSWORD is a string like -e foo or /etc/*, that's going to create problems.
Quote the input and avoid echo altogether. While you're at it, whitelist the checksum output, making head redundant:
HASHED=$( tr -d '\n' <<<"$GUAC_PASSWORD" | sha256sum | tr -dc a-f0-9 )
edit: suppress newline added by <<<
2
Use sort's -u and -o switches:
find … | sort -u - $file -o $file
1
I recommend starting the script with a shebang so it can be executed as a program:
#!/bin/bash
As there's nothing in here that isn't standard shell, then we can make it leaner by using plain POSIX shell instead:
#!/bin/sh
I recommend set -eu, to cause the shell to abort in more error cases.
We can save one fork by using exec for the final command. In ...
1
Well, to be honest I am not exactly sure what do you want to review :) This isn't a script. It is just standard zip command.
Maybe you should think about this: ${war}/mediawiki_general_backups/${domain}-directory-backup-${date}.zip. It is too long and ugly. Try to add more these things into your script and a readability will be lost.
I fear I don't have ...
1
I like the script. But I have maybe some suggestions for improvement.
This part:
RAM=$(free -m)
total=$(echo "$RAM"|awk '/^[mM]em\.?:/{print $2}')
available=$(echo "$RAM"|awk '/^[mM]em\.?:/{print $7}')
Personalty I prefer to dig these values from /proc/meminfo to avoid running unnecessary free utility, but I saw several scripts based on it. And in case ...
3
Naming
Try not to use generic names like $file. Make your code read easy for others. Say $files_to_backup for example.
Check for errors when it matters
If backup is important: check that the backups succeeded:
if cp "${files[@]}"${war}/mediawiki_specific_backups";then
rm -rf "${war}/${domain}"
mkdir "${war}/${domain}"
...
...
else
#...
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