Tag Archives: Bash Script

Array Assignments List Assignment If you are familiar with Perl, C, or Java, you might think that Bash would use commas to separate array elements,however this is not the case; …

Infinite Loop while true; do echo ok done or while :; do echo ok done or until false; do echo ok done Function Return function positive() { return 0 } …

Parameter to [ or testDetailsFile OperatorsDetails-e “$file“Returns true if the file exists.-d “$file“ Returns true if the file exists and is a directory-f “$file“ Returns true if the file exists …

ParameterDetailsinternal file descriptorAn integerdirectionOne of >, < or <> Redirecting standard output redirect the standard output (aka STDOUT) of the current command into a file or another descriptor. These examples …

Job handling Creating jobs To create an job, just append a single & after the command: $ sleep 10 & [1] 20024 You can also make a running process a …

Shell aliases are a simple way to create new commands or to wrap existing commands with code of your own. Theysomewhat overlap with shell functions, which are however more versatile …

How to search a file for a pattern To find the word foo in the file bar : grep foo ~/Desktop/bar To find all lines that do not contain foo …

Option Description-nPrint line numbers-vShow non-printing characters using ^ and M- notation except LFD and TAB-TShow TAB characters as ^I-EShow linefeed(LF) characters as $-eSame as -vE-bNumber nonempty output lines, overrides -n-Aequivalent …

Option Description-a, –allList all entries including ones that start with a dot-A, –almost-allList all entries excluding . and ..-cSort files by change time-d, –directoryList directory entries-h, –human-readableShow sizes in human …

Absolute vs relative directories To change to an absolutely specified directory, use the entire name, starting with a backslash \, thus: cd /home/username/project/abc If you want to change to a …