To declare an associative array in bash, all you have to do is use thedeclarecommand with the-Aflag along with the name of the array as shown here: declare -A Array_name For example, if I want to declare an associative array namedLHB, then I would use the following command: declare ...
Thepatternwillmatchif itmatchesanypartofthe string. Anchor thepatternusingthe ‘^’and‘$’ regular expression operatorstoforce ittomatchthe entire string. Thearrayvariable BASH_REMATCH records which partsofthe string matched the pattern. The elementofBASH_REMATCHwithindex0containstheportionofthe string...
Check if a Key Exists A simple way to check if an element exists in an array is to use a conditionalifstatement. For example: if [[ -n "${example_array["key1"]}" ]] then echo "True" else echo "False" fiCopy The-ntag checks if the array returns a non-zero element when search...
echo "${my_assoc_array[shape]}" # Output: circle Removing a Key unset my_assoc_array[color] echo "${!my_assoc_array[@]}" # Output: fruit shape Checking If a Key Exists: if [[ -v my_assoc_array[fruit] ]]; then echo "Key 'fruit' exists!" fi Output: Key 'fruit' exists! 3...
我想检查动物是否存在: if [ -z "$animals[horse]"]; then echo "horse exists"; fi 但这不起作用。 在bash 4.3,可以将操作员应用于阵列。 -vbash 5个回答 28投票 在先前的版本中,您需要更加谨慎地区分未存在的密钥和参考任何空字符串的密钥。 declare -A animals animals[horse]=neigh # Fish...
NAME must not be supplied if command is a simple command (see above); otherwise, it is interpreted as the first word of the simple command. When the coprocess is executed, the shell creates an array variable (see Arrays below) named NAME in the context of the exe‐ ...
As we can see, though, this approach iterates through the array and prints only the value associated with each key, which are of no interest when using the associative array as a set. 3.4. Membership Testing To determine if an element (key) exists within the set, we can use the same ...
checkeq(1) checknr(1) chgrp(1) chgrp(1g) chkey(1) chmod(1) chmod(1g) chown(1) chown(1B) chown(1g) chroot(1g) ckdate(1) ckgid(1) ckint(1) ckitem(1) ckkeywd(1) ckpath(1) ckrange(1) ckstr(1) cksum(1) cksum(1g) cktime(1) ckuid(1) ckyorn(1) clear(1) clear(...
if [[ ${arr[*]} == *sub_string* ]]; then printf '%s\n' "sub_string is in array." fiUsing a case statement:case "$var" in *sub_string*) # Do stuff ;; *sub_string2*) # Do more stuff ;; *) # Else ;; esacCheck if string starts with sub-stringif [[ $var == sub_...
如果要将文件全部存入 Onedrive 能备份的文件夹中，或者是将文件直接放入 Onedrive 的文件夹，这样十分的...