Use tee –append or tee -a. echo ‘deb blah … blah’ | sudo tee -a /etc/apt/sources.list Make sure to avoid quotes inside quotes. To avoid printing data back to the console, redirect the output to /dev/null. echo ‘deb blah … blah’ | sudo tee -a /etc/apt/sources.list > /dev/null Remember about the (-a/–append) flag! Just tee … Read more
The easiest way is to use sed (or perl): sed -i -e ‘s/abc/XYZ/g’ /tmp/file.txt Which will invoke sed to do an in-place edit due to the -i option. This can be called from bash. If you really really want to use just bash, then the following can work: while IFS=” read -r a; do echo … Read more
curl -s http://google.com > temp.html works for curl version 7.19.5 on Ubuntu 9.10 (no progress bar). But if for some reason that does not work on your platform, you could always redirect stderr to /dev/null: curl http://google.com 2>/dev/null > temp.html
Try tail: tail -n +2 “$FILE” -n x: Just print the last x lines. tail -n 5 would give you the last 5 lines of the input. The + sign kind of inverts the argument and make tail print anything but the first x-1 lines. tail -n +1 would print the whole file, tail -n … Read more
#!/bin/bash cd “$(dirname “$0″)”
me=`basename “$0″` For reading through a symlink1, which is usually not what you want (you usually don’t want to confuse the user this way), try: me=”$(basename “$(test -L “$0” && readlink “$0” || echo “$0″)”)” IMO, that’ll produce confusing output. “I ran foo.sh, but it’s saying I’m running bar.sh!? Must be a bug!” Besides, one … Read more
For string equality comparison, use: if [[ “$s1” == “$s2” ]] For string does NOT equal comparison, use: if [[ “$s1” != “$s2” ]] For the a contains b, use: if [[ $s1 == *”$s2″* ]] (and make sure to add spaces between the symbols): Bad: if [[“$s1” == “$s2”]] Good: if [[ “$s1” == … Read more
Try this statement: exit 1 Replace 1 with appropriate error codes. See also Exit Codes With Special Meanings.
The cat <<EOF syntax is very useful when working with multi-line text in Bash, eg. when assigning multi-line string to a shell variable, file or a pipe. Examples of cat <<EOF syntax usage in Bash: 1. Assign multi-line string to a shell variable $ sql=$(cat <<EOF SELECT foo, bar FROM db WHERE foo=’baz’ EOF ) … Read more
Prerequisites: You need to be able to run PowerShell as an administrator You need to set your PowerShell execution policy to a permissive value or be able to bypass it Steps: Launch Windows PowerShell as an Administrator, and wait for the PS> prompt to appear Navigate within PowerShell to the directory where the script lives: … Read more