First, let’s demonstrate that head is actually working correctly: $ printf ‘\xef\xbb\xbf’ >file $ head -c 3 file $ head -c 3 file | hexdump -C 00000000 ef bb bf |…| 00000003 Now, let’s create a working function has_bom. If your grep supports -P, then one option is: $ has_bom() { head -c3 “$1” | … Read more
You can install aspell with Homebrew on OS X. brew info aspell lists supported languages. brew install aspell –lang=en,fi,jp aspell check opens a file in an interactive spell checker: for f in *.txt; do aspell check $f; done aspell list prints all unrecognized words: cat *.txt | aspell list | sort -u Learned words are … Read more
You won’t lose commits by closing the terminal. ctrl+c will exit the prompt > What happened was you opened up a string with the odd number of ‘ characters. Bash expects more input for your string, and allows you to enter it after the > prompt. Try typing ‘ and hit return, you will get … Read more
/usr/bin/env exports values passed in key=value pairs into the environment of any program it’s used to invoke. kubectl -n nmspc exec “$POD” — env curIP=123 script01 Note that you should never use $runScript or any other unquoted expansion to invoke a shell command. See BashFAQ #50 — I’m trying to put a command in a … Read more
NAME paste — merge corresponding or subsequent lines of files SYNOPSIS paste [-s] [-d list] file … DESCRIPTION The paste utility concatenates the corresponding lines of the given input files, replacing all but the last file’s newline characters with a single tab character, and writes the resulting lines to standard output.
Bash does not support local functions, but depending on your specific script and architecture you can control the scope of your function name through subshells. By replacing the {..} with (..) in your definition, you’ll get the output you want. The new definition of usage will be limited to the function, but so will e.g. … Read more
The user’s chosen editor should be in $EDITOR, but you must still choose a sane default. “${EDITOR:-vi}” file.txt
KEYDEF is F[.C][OPTS][,F[.C][OPTS]] for start and stop position, where F is a field number and C a character position in the field; both are origin 1, and the stop position defaults to the line’s end. If neither -t nor -b is in effect, characters in a field are counted from the beginning of the preceding … Read more
declare inside a function doesn’t work as expected. I needed read-only global variables declared in a function. I tried this inside a function but it didn’t work: declare -r MY_VAR=1 But this didn’t work. Using the readonly command did: func() { readonly MY_VAR=1 } func echo $MY_VAR MY_VAR=2 This will print 1 and give the … Read more
SOLUTION: I am posting my answer to my own question here as recommended. This solution works for Bash 4.4+, since, starting with that version of Bash, version 7.0 of the GNU readline library is used, which includes the necessary additions of the vi-cmd-mode-string and vi-ins-mode-string variables. These variables can be set as follows in your … Read more