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| [[Anchor(faq67)]] == How can I trim leading/trailing white space from one of my variables? == There are a few ways to do this -- none of them elegant. First, the most portable way would be to use sed: {{{ x=$(echo "$x" | sed -e 's/^ *//' -e 's/ *$//') # Note: this only removes spaces. For tabs too: x=$(echo "$x" | sed -e $'s/^[ \t]*//' -e $'s/[ \t]*$//') # Or possibly, with some systems: x=$(echo "$x" | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//') }}} One can achieve the goal using builtins, although at the moment I'm not sure which shells the following syntax supports: {{{ # Remove leading whitespace: while [[ $x = [$' \t\n']* ]]; do x=${x#[$' \t\n']}; done # And now trailing: while [[ $x = *[$' \t\n'] ]]; do x=${x%[$' \t\n']}; done }}} Of course, the preceding example is pretty slow, because it removes one character at a time, in a loop (although it's good enough in practice for most purposes). If you want something a bit fancier, there's a bash-only solution using extglob: {{{ shopt -s extglob x=${x##+([$' \t\n'])}; x=${x%%+([$' \t\n'])} shopt -u extglob }}} Rather than specify each type of space character yourself, you can use character classes. Two character classes that are useful for matching whitespace are space and blank. More info: ctype/wctype(3), re_format/regex(7), isspace(3). {{{ shopt -s extglob x=${x##+([[:space:]])}; x=${x%%+([[:space:]])} shopt -u extglob }}} There are many, many other ways to do this. These are not necessarily the most efficient, but they're known to work. |
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My name is Valentine. Alaska is where my house is. Fencing is the only pastime her partner doesn't authorize of. After running out his job for several years he ended up being a hotel receptionist. Have a look at the most recent news on my site: https://www.youtube.com/watch?v=S6joRgSfOxA<<BR>><<BR>>
Here is my web blog: Rejuvenate with Dr. Marks