Use a ~/.bash_completion file. From the Bash Completion FAQ: Q. How can I insert my own local completions without having to reinsert them every time you issue a new release? A. Put them in ~/.bash_completion, which is parsed at the end of the main completion script. See also the next question. Q. I author/maintain package … Read more
If you read the man page for bash you’ll find the following at the top of the OPTIONS section: All of the single-character shell options documented in the description of the set builtin command can be used as options when the shell is invoked. In addition, bash interprets the following options when it is invoked… … Read more
bash -x script or set -x in the script. You can unset the option again with set +x. If you just want to do it for a few commands you can use a subshell: `(set -x; command1; command; …;)
This will put your text into your variable without needing to escape the quotes. It will also handle unbalanced quotes (apostrophes, i.e. ‘). Putting quotes around the sentinel (EOF) prevents the text from undergoing parameter expansion. The -d” causes it to read multiple lines (ignore newlines). read is a Bash built-in so it doesn’t require … Read more
command 2> >(while read line; do echo -e “\e[01;31m$line\e[0m” >&2; done)
This can be easily done with temporary named pipes: bash –init-file <(echo “ls; pwd”) Credit for this answer goes to the comment from Lie Ryan. I found this really useful, and it’s less noticeable in the comments, so I thought it should be its own answer.
Supposing your array is $errors, just check to see if the count of elements is zero. if [ ${#errors[@]} -eq 0 ]; then echo “No errors, hooray” else echo “Oops, something went wrong…” fi
See the uuidgen program which is part of the e2fsprogs package. According to this, libuuid is now part of util-linux and the inclusion in e2fsprogs is being phased out. However, on new Ubuntu systems, uuidgen is now in the uuid-runtime package. To create a uuid and save it in a variable: uuid=$(uuidgen) On my Ubuntu … Read more
This: date +%s will return the number of seconds since the epoch. This: date +%s%N returns the seconds and current nanoseconds. So: date +%s%N | cut -b1-13 will give you the number of milliseconds since the epoch – current seconds plus the left three of the nanoseconds. and from MikeyB – echo $(($(date +%s%N)/1000000)) (dividing … Read more
There are several differences. In my opinion, a few of the most important are: [ is a builtin in Bash and many other modern shells. The builtin [ is similar to test with the additional requirement of a closing ]. The builtins [ and test imitate the functionality /bin/[ and /bin/test along with their limitations … Read more