The manpage for bash v3.2.48 says: […] The format for arithmetic expansion is: $((expression)) The old format $[expression] is deprecated and will be removed in upcoming versions of bash. So $[…] is old syntax that should not be used anymore.
Your grep is probably removing ls‘s color codes because it has its own coloring turned on. You “could” do this: ls -l –color=always | grep –color=never pattern However, it is very important that you understand what exactly you’re grepping here. Not only is grepping ls unnecessary (use a glob instead), this particular case is grepping … Read more
The thing with while loops is that they tend to process one item at a time, often when it’s unnecessary. This is where xargs has an advantage – it can batch up the arguments to allow one command to process lots of items. For example, a while loop: pax> echo ‘1 2 3 4 5’ … Read more
In terms of syntactic grouping, > and < have higher precedence; that is, these two commands are equivalent: sort < names | head ( sort < names ) | head as are these two: ls | sort > out.txt ls | ( sort > out.txt ) But in terms of sequential ordering, | is performed … Read more
yes, there is way to do this. That is, as long as your terminal supports ANSI escape sequences. This is most terminals that exist. I think I don’t need explain how to grep, sed etc. point is the color right? see below, this will make WARN yellow ERROR red foo green here is example: kent$ … Read more
% is a special character for crontab. From man 5 crontab: The “sixth” field (the rest of the line) specifies the command to be run. The entire command portion of the line, up to a newline or a “%” character, will be executed by /bin/sh or by the shell specified in the SHELL variable of … Read more
The option you need is “CONFIG+=debug”. See General Configuration in qmake Manual. #!/bin/bash qmake CONFIG+=debug ${qmake_options} make ${make_options}
Well, you can’t nest ${var%}/${var#} operations, so you’ll have to use temporary variable. Like here: var=”http://whatever/score/” temp_var=”${var#http://}” echo “${temp_var%/score/}” Alternatively, you can use regular expressions with (for example) sed: some_variable=”$( echo “$var” | sed -e ‘s#^http://##; s#/score/$##’ )”
On windows you might need to start the ssh agent like this # start the ssh-agent in the background $ eval $(ssh-agent -s) > Agent pid 59566 Add your SSH private key to the ssh-agent. If you created your key with a different name, or if you are adding an existing key that has a … Read more
#!/bin/bash FILES=/home/shep/Desktop/test/* for f in $FILES do if [[ “$f” != *\.* ]] then DO STUFF fi done