cmd >>file.txt 2>&1 Bash executes the redirects from left to right as follows: >>file.txt: Open file.txt in append mode and redirect stdout there. 2>&1: Redirect stderr to “where stdout is currently going”. In this case, that is a file opened in append mode. In other words, the &1 reuses the file descriptor which stdout currently … Read more
Try: find . -name ‘*.php’ | xargs wc -l or (when file names include special characters such as spaces) find . -name ‘*.php’ | sed ‘s/.*/”&”/’ | xargs wc -l The SLOCCount tool may help as well. It will give an accurate source lines of code count for whatever hierarchy you point it at, as … Read more
for i in $(seq 1 $END); do echo $i; done edit: I prefer seq over the other methods because I can actually remember it 😉
You can enter the long form command: source ~/.bashrc or you can use the shorter version of the command: . ~/.bashrc
(Usually) The right way if [ -z ${var+x} ]; then echo “var is unset”; else echo “var is set to ‘$var'”; fi where ${var+x} is a parameter expansion which evaluates to nothing if var is unset, and substitutes the string x otherwise. Quotes Digression Quotes can be omitted (so we can say ${var+x} instead of … Read more
In addition to backticks `command`, command substitution can be done with $(command) or “$(command)”, which I find easier to read, and allows for nesting. OUTPUT=$(ls -1) echo “${OUTPUT}” MULTILINE=$(ls \ -1) echo “${MULTILINE}” Quoting (“) does matter to preserve multi-line variable values; it is optional on the right-hand side of an assignment, as word splitting … Read more
Bash Space-Separated (e.g., –option argument) cat >/tmp/demo-space-separated.sh <<‘EOF’ #!/bin/bash POSITIONAL_ARGS=() while [[ $# -gt 0 ]]; do case $1 in -e|–extension) EXTENSION=”$2″ shift # past argument shift # past value ;; -s|–searchpath) SEARCHPATH=”$2″ shift # past argument shift # past value ;; –default) DEFAULT=YES shift # past argument ;; -*|–*) echo “Unknown option $1” exit … Read more
First, get file name without the path: filename=$(basename — “$fullfile”) extension=”${filename##*.}” filename=”${filename%.*}” Alternatively, you can focus on the last “https://stackoverflow.com/” of the path instead of the ‘.’ which should work even if you have unpredictable file extensions: filename=”${fullfile##*/}” You may want to check the documentation : On the web at section “3.5.3 Shell Parameter Expansion” … Read more
You can set the internal field separator (IFS) variable, and then let it parse into an array. When this happens in a command, then the assignment to IFS only takes place to that single command’s environment (to read ). It then parses the input according to the IFS variable value into an array, which we … Read more
Answer POSIX compatible: command -v <the_command> Example use: if ! command -v <the_command> &> /dev/null then echo “<the_command> could not be found” exit fi For Bash specific environments: hash <the_command> # For regular commands. Or… type <the_command> # To check built-ins and keywords Explanation Avoid which. Not only is it an external process you’re launching … Read more