has

L_HAS_ is a collection of functions to detect bash features.

if ((L_HAS_SRANDOM)); then
  echo "SRANDOM is supported $SRANDOM"
else
  echo "SRANDOM is not supported"
fi

has ¶

Set of integer variables for checking if Bash has specific feature.

$L_BASH_VERSION ¶

Bash version expressed as a hexadecimal integer variable with digits 0xMMIIPP, where MM is major part, II is minor part and PP is patch part of version.

Shellcheck disable= SC2004

$L_HAS_BASH5_3 ¶

$L_HAS_BASH5_2 ¶

$L_HAS_BASH5_1 ¶

$L_HAS_BASH5_0 ¶

$L_HAS_BASH4_4 ¶

$L_HAS_BASH4_3 ¶

$L_HAS_BASH4_2 ¶

$L_HAS_BASH4_1 ¶

$L_HAS_BASH4_0 ¶

$L_HAS_BASH3_2 ¶

$L_HAS_BASH3_1 ¶

$L_HAS_BASH3_0 ¶

$L_HAS_BASH2_5 ¶

$L_HAS_BASH2_4 ¶

$L_HAS_BASH2_3 ¶

$L_HAS_BASH2_2 ¶

$L_HAS_BASH2_1 ¶

$L_HAS_BASH2_0 ¶

$L_HAS_BASH1_14_7 ¶

$L_HAS_COMPGEN_V ¶

`compgen' has a new option: -V varname. If supplied, it stores the generated

$L_HAS_NO_FORK_COMMAND_SUBSTITUTION ¶

New form of command substitution: ${ command; } or ${|command;} to capture

$L_HAS_PATSUB_REPLACEMENT ¶

New shell option: patsub_replacement. When enabled, a `&' in the replacement

$L_HAS_k_EXPANSION ¶

There is a new parameter transformation operator: @k. This is like @K, but

$L_HAS_SRANDOM ¶

SRANDOM: a new variable that expands to a 32-bit random number

$L_HAS_UuLK_EXPASIONS ¶

New U',u', and `L' parameter transformations to convert to uppercas New `K' parameter transformation to display associative arrays as key-

$L_HAS_QEPAa_EXPANSIONS ¶

There is a new ${parameter@spec} family of operators to transform the value of `parameter'.

$L_HAS_LOCAL_DASH ¶

Bash 4.4 introduced function scoped local -

$L_HAS_MAPFILE_D ¶

The `mapfile' builtin now has a -d option

$L_HAS_DECLARE_WITH_NO_QUOTES ¶

The declare builtin no longer displays array variables using the compound

assignment syntax with quotes; that will generate warnings when re-used as input, and isn't necessary. Declare -p on Bash<4.4 adds extra $'\001' before $'\001' and $'\177' bytes.

$L_HAS_NAMEREF ¶

Bash 4.3 introduced declare -n nameref

$L_HAS_PRINTF_T ¶

The printf builtin has a new %(fmt)T specifier

$L_HAS_VARIABLE_FD ¶

If the optional left-hand-side of a redirection is of the form {var},

$L_HAS_EXTGLOB_IN_TESTTEST ¶

Force extglob on temporarily when parsing the pattern argument to

the == and != operators to the [[ command, for compatibility.

$L_HAS_TEST_V ¶

Bash 4.1 introduced test/[/[[ -v variable unary operator

$L_HAS_PRINTF_V_ARRAY ¶

`printf -v' can now assign values to array indices.

$L_HAS_ASSOCIATIVE_ARRAY ¶

Bash 4.0 introduced declare -A var=([a]=b)

$L_HAS_MAPFILE ¶

Bash 4.0 introduced mapfile

$L_HAS_READARRAY ¶

Bash 4.0 introduced readarray

$L_HAS_CASE_FALLTHROUGH ¶

Bash 4.0 introduced case fallthrough ;& and ;;&

$L_HAS_LOWERCASE_UPPERCASE_EXPANSION ¶

Bash 4.0 introduced ${var,,} and ${var^^} expansions

$L_HAS_BASHPID ¶

Bash 4.0 introduced BASHPID variable

$L_HAS_COPROC ¶

Bash 3.2 introduced coproc

$L_HAS_UNQUOTED_REGEX ¶

[[ =~ has to be quoted or not, no one knows.

Bash4.0 change: The shell now has the notion of a compatibility level', controlled by new variables settable byshopt'. Setting this variable currently restores the bash-3.1 behavior when processing quoted strings on the rhs of the =~' operator to the[[' command. Bash3.2 change: Quoting the string argument to the [[ command's =~ operator now forces string matching, as with the other pattern-matching operators.

$L_HAS_PREFIX_EXPANSION ¶

Bash 2.4 introduced ${!prefix*} expansion

$L_HAS_HERE_STRING ¶

Bash 2.05 introduced <<<"string"

$L_HAS_INDIRECT_EXPANSION ¶

Bash 2.0 introduced ${!var} expansion

$L_HAS_ARRAY ¶

Bash 1.14.7 introduced arrays

Bash 1.14.7 also introduced: New variables: DIRSTACK, PIPESTATUS, BASH_VERSINFO, HOSTNAME, SHELLOPTS, MACHTYPE. The first three are array variables.