Menu
Say a string might be like "a b '' c '' d". How can I check that there is single/double quote and space contained in the string?
249
To find out if a bash variable is empty: Return true if a bash variable is unset or set to the empty string: if [ -z "$var" ]; Another option: [ -z "$var" ] && echo "Empty" Determine if a bash variable is empty: [[ ! -z "$var" ]] && echo "Not empty" || echo "Empty"
A regular expression matching sign, the =~ operator, is used to identify regular expressions. Perl has a similar operator for regular expression corresponding, which stimulated this operator.
Filename with Spaces in Bash A simple method will be to rename the file that you are trying to access and remove spaces. Some other methods are using single or double quotations on the file name with spaces or using escape (\) symbol right before the space.
Char. Whitespace — this is a tab, newline, vertical tab, form feed, carriage return, or space. Bash uses whitespace to determine where words begin and end. The first word is the command name and additional words become arguments to that command.
You can use regular expressions in bash:
string="a b '' c '' d" if [[ "$string" =~ \ |\' ]] # slightly more readable: if [[ "$string" =~ ( |\') ]] then echo "Matches" else echo "No matches" fi Edit:
For reasons obvious above, it's better to put the regex in a variable:
pattern=" |'" if [[ $string =~ $pattern ]] And quotes aren't necessary inside double square brackets. They can't be used on the right or the regex is changed to a literal string.
126
case "$var" in *\ * ) echo "match" ;; *) echo "no match" ;; esac If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
