Your problem is that you want an array, but you wrote a single string that contains the elements with spaces between them. Use an array instead. WHITELIST_DOMAINS=(‘*’ ‘*.foo.com’ ‘*.bar.com’) Always use double quotes around variable substitutions (i.e. “$foo”), otherwise the shell splits the the value of the variable into separate words and treats each word … Read more
As others have pointed out, using cat or awk instead of a read-echo loop is a much better way to do this — avoids the whitespace-trimming problem (and a couple of others you haven’t stumbled upon), runs faster, and at least with cat, is simply cleaner code. Nonetheless, I’d like to take a stab at … Read more
Use an Awk as below, awk ‘{ seen[$1] += $2 } END { for (i in seen) print i, seen[i] }’ file1 1486113768 9936 1486113769 6160736 1486113770 5122176 1486113772 4096832 1486113773 9229920 1486113774 8568888 {seen[$1]+=$2} creates a hash-map with the $1 being treated as the index value and the sum is incremented only for those … Read more
$(echo foo bar) is indeed a command substitution. In this specific example, you don’t need double quotes because a variable assignment creates a “double quote context” for its right-hand side, so VAR=$(…) is equivalent to VAR=”$(…)”. In bash, you don’t need double quotes in export VAR=$(…) or declare VAR=$(…). But you do need the double … Read more
You can use wait to wait for all the background processes started by userscript to complete. Since wait only works on children of the current shell, you’ll need to source their script instead of running it as a separate process. ( source userscript; wait ) Sourcing the script in an explicit subshell should simulate starting … Read more
Use another FD. while read line; do if ! read -u 3 line2 then break fi echo “$line***$line2” done < file1.csv 3< file2.csv
Another approach, for fun, using regular expressions: regex=’prefix – (.*) – suffix.txt’ for f in *.txt; do [[ $f =~ $regex ]] && mv “$f” “${BASH_REMATCH[1]}.txt” done Actually, using the simple pattern ‘*.txt’ here has two problems: It’s too broad; you may need to apply the regex to a lot of non-matching files. If there … Read more
To work around this recent regression in Docker, execute: stty onlcr This adds an implicit carriage return after each newline. CharlessMacBook:~ cduffy$ docker run -t -i bash bash-4.4# bash-4.4# bash-4.4# stty onlcr bash-4.4# bash-4.4# bash-4.4#
Your condition should be: if [ $? -ne 0 ] GCC will return zero on success, or something else on failure. That line says “if the last command returned something other than zero.”
Since you’re expecting newlines, you can simply replace all instances of mm in your string with a newline. In pure native bash: in=’emmbbmmaaddsb’ sep=’mm’ printf ‘%s\n’ “${in//$sep/$’\n’}” If you wanted to do such a replacement on a longer input stream, you might be better off using awk, as bash’s built-in string manipulation doesn’t scale well … Read more