This line of code works in Linux, but doesn’t in OSX. What am I missing?

pwd=$(echo "$password_file" | openssl enc -aes-256-cbc -md sha512 -a -d -pbkdf2 -iter 100000 -salt -pass "pass:$salt_password")

On Linux, it outputs the decrypted text.
On OSX, it just gives openssl usage info, but no error, and no decrypted text.

Here’s the code in full context:

#!/bin/bash
SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"

# password_file="$SCRIPT_DIR/test_passfile_2.ssl"
password_file="U2FsdGVkX18RH4KXM5Ldz0Q2ny8RQegoaDPObu50Y6k="
salt_password="salt password"

# Decrypt password file or encrypted passwrod string if provided
if [ -n "$password_file" ]; then
    if [ -f "$password_file" ]; then
        echo "Decrypting password file using salt password..."
        pwd=$(cat "$password_file" | openssl enc -aes-256-cbc -md sha512 -a -d -pbkdf2 -iter 100000 -salt -pass "pass:$salt_password")
    else
        echo "Decrypting password string using salt password..."
        pwd=$(echo "$password_file" | openssl enc -aes-256-cbc -md sha512 -a -d -pbkdf2 -iter 100000 -salt -pass "pass:$salt_password")
    fi

    esc() {
        printf "%s" "$1" | sed -e "s/'//g"
    }
    
    # utilize the function so that we don't need to quote pwd.
    password=$(esc "${pwd}")
    unset pwd

    if [ $? -ne 0 ]; then
        echo "Error: Failed to decrypt password."
        exit 1
    fi
    echo "Password decrypted successfully."
fi
 
echo $password  # Should output 'test'

Here’s the OSX terminal output:

usage: enc -ciphername [-AadePp] [-base64] [-bufsize number] [-debug]
    [-in file] [-iv IV] [-K key] [-k password]
    [-kfile file] [-md digest] [-none] [-nopad] [-nosalt]
    [-out file] [-pass arg] [-S salt] [-salt]

 -A                 Process base64 data on one line (requires -a)
 -a                 Perform base64 encoding/decoding (alias -base64)
 -bufsize size      Specify the buffer size to use for I/O
 -d                 Decrypt the input data
 -debug             Print debugging information
 -e                 Encrypt the input data (default)
 -in file           Input file to read from (default stdin)
 -iv IV             IV to use, specified as a hexadecimal string
 -K key             Key to use, specified as a hexadecimal string
 -md digest         Digest to use to create a key from the passphrase
 -none              Use NULL cipher (no encryption or decryption)
 -nopad             Disable standard block padding
 -out file          Output file to write to (default stdout)
 -P                 Print out the salt, key and IV used, then exit
                      (no encryption or decryption is performed)
 -p                 Print out the salt, key and IV used
 -pass source       Password source
 -S salt            Salt to use, specified as a hexadecimal string
 -salt              Use a salt in the key derivation routines (default)
 -v                 Verbose

Valid ciphername values:

 -aes-128-cbc              -aes-128-cbc-hmac-sha1    -aes-128-cfb            
 -aes-128-cfb1             -aes-128-cfb8             -aes-128-ctr            
 -aes-128-ecb              -aes-128-gcm              -aes-128-ofb            
 -aes-128-xts              -aes-192-cbc              -aes-192-cfb            
 -aes-192-cfb1             -aes-192-cfb8             -aes-192-ctr            
 -aes-192-ecb              -aes-192-gcm              -aes-192-ofb            
 -aes-256-cbc              -aes-256-cbc-hmac-sha1    -aes-256-cfb            
 -aes-256-cfb1             -aes-256-cfb8             -aes-256-ctr            
 -aes-256-ecb              -aes-256-gcm              -aes-256-ofb            
 -aes-256-xts              -aes128                   -aes192                  
 -aes256                   -bf                       -bf-cbc                  
 -bf-cfb                   -bf-ecb                   -bf-ofb                  
 -blowfish                 -camellia-128-cbc         -camellia-128-cfb        
 -camellia-128-cfb1        -camellia-128-cfb8        -camellia-128-ecb        
 -camellia-128-ofb         -camellia-192-cbc         -camellia-192-cfb        
 -camellia-192-cfb1        -camellia-192-cfb8        -camellia-192-ecb        
 -camellia-192-ofb         -camellia-256-cbc         -camellia-256-cfb        
 -camellia-256-cfb1        -camellia-256-cfb8        -camellia-256-ecb        
 -camellia-256-ofb         -camellia128              -camellia192            
 -camellia256              -cast                     -cast-cbc                
 -cast5-cbc                -cast5-cfb                -cast5-ecb              
 -cast5-ofb                -chacha                   -des                    
 -des-cbc                  -des-cfb                  -des-cfb1                
 -des-cfb8                 -des-ecb                  -des-ede                
 -des-ede-cbc              -des-ede-cfb              -des-ede-ofb            
 -des-ede3                 -des-ede3-cbc             -des-ede3-cfb            
 -des-ede3-cfb1            -des-ede3-cfb8            -des-ede3-ofb            
 -des-ofb                  -des3                     -desx                    
 -desx-cbc                 -gost89                   -gost89-cnt              
 -gost89-ecb               -id-aes128-GCM            -id-aes192-GCM          
 -id-aes256-GCM            -rc2                      -rc2-40-cbc              
 -rc2-64-cbc               -rc2-cbc                  -rc2-cfb                
 -rc2-ecb                  -rc2-ofb                  -rc4                    
 -rc4-40                   -rc4-hmac-md5