I’m trying to switch PHP version from 8.1 to 7.1 and run composer install. Here’s my method:-
cd /etc/php && ls -la
drwxr-xr-x 4 root root 4096 Jan 27 09:18 .
drwxr-xr-x 141 root root 12288 Jan 27 09:18 ..
drwxr-xr-x 5 root root 4096 Jan 27 09:18 7.1
drwxr-xr-x 4 root root 4096 Dec 5 20:21 8.1
php -v
PHP 8.1.2-1ubuntu2.10 (cli) (built: Jan 16 2023 15:19:49) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.1.2, Copyright (c) Zend Technologies
with Zend OPcache v8.1.2-1ubuntu2.10, Copyright (c), by Zend Technologies
with Xdebug v3.1.2, Copyright (c) 2002-2021, by Derick Rethans
composer
______
/ ____/___ ____ ___ ____ ____ ________ _____
/ / / __ / __ `__ / __ / __ / ___/ _ / ___/
/ /___/ /_/ / / / / / / /_/ / /_/ (__ ) __/ /
____/____/_/ /_/ /_/ .___/____/____/___/_/
/_/
Composer 2.2.6 2022-02-04 17:00:38
...
However, upon switching PHP versions, from 8.1 to 7.1, I get an error…
update-alternatives --config php
There are 3 choices for the alternative php (providing /usr/bin/php).
Selection Path Priority Status
------------------------------------------------------------
0 /usr/bin/php.default 100 auto mode
1 /usr/bin/php.default 100 manual mode
2 /usr/bin/php7.1 71 manual mode
* 3 /usr/bin/php8.1 81 manual mode
Press <enter> to keep the current choice[*], or type selection number:
2
php -v
PHP 7.1.33-51+ubuntu22.04.1+deb.sury.org+1 (cli) (built: Jan 6 2023 15:54:36) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2018 Zend Technologies
with Zend OPcache v7.1.33-51+ubuntu22.04.1+deb.sury.org+1, Copyright (c) 1999-2018, by Zend Technologies
composer
PHP Parse error: syntax error, unexpected '|', expecting variable (T_VARIABLE) in /usr/share/php/Composer/IO/BaseIO.php on line 163
Parse error: syntax error, unexpected '|', expecting variable (T_VARIABLE) in /usr/share/php/Composer/IO/BaseIO.php on line 163
help