The main flaw of using a here document is that the script’s standard input will be the here document. So if you have a script which wants to process its standard input, python -c is pretty much your only option. On the other hand, using python -c ‘…’ ties up the single-quote for the shell’s … Read more
Neither standard nor extended regular expressions support the look behind. Use Perl compatible regexes: grep -P ‘(?<!\\)xxx’ test.tex
you need to add backslash to get it evaluated not in the time of FOO assigment but during evaluating the PS1, so do: export PS1=”[\$FOO]$ ” instead of: export PS1=”[$FOO]$ ” Note the \ before the $FOO.
EDIT: As mentioned by Marie and James if you only want to run the command if it exists, npm has an option for that: npm run test –if-present This way you can have a generic script that work with multiple projects (that may or may not have an specific task) without having the risk of … Read more
Some things won’t respond to Ctrl+C; in that case, you can also do Ctrl+Z which stops the process and then kill %1 – or even fg to go back to it. Read the section in man bash entitled “JOB CONTROL” for more information. It’s very helpful. (If you’re not familiar with man or the man … Read more
Welcome to bash. It’s an old, dark and mysterious thing, capable of great magic. 🙂 The option you’re asking about is for the find command though, not for bash. From your command line, you can man find to see the options. The one you’re looking for is -o for “or”: list=”$(find /home/user/Desktop -name ‘*.bmp’ -o … Read more
Finally I find THE solution: convert in.pdf -append out%d.png Thanks to this post. edit As a plus, the opposite operation is: convert *.png output.pdf or if you have foo1.png, foo2.png..fooN.png convert foo?.png output.pdf Notice that does not work with foo01.png, foo02.png..foo0N.png
You need to supply the -L or –location option in order to enable curl to follow HTTP redirects. Quoting from man curl: -L, –location (HTTP/HTTPS) If the server reports that the requested page has moved to a different location (indicated with a Location: header and a 3XX response code), this option will make curl redo … Read more
In jq 1.3 and up you can use the –arg VARIABLE VALUE command-line option: jq -n –arg v “$VAR” ‘{“foo”: $v}’ I.e., –arg sets a variable to the given value so you can then use $varname in your jq program, and now you don’t have to use shell variable interpolation into your jq program. EDIT: … Read more