mv composer.phar / usr / local / bin / composer mv：尝试覆盖'/ usr / local / bin / composer'，覆盖模式0755（rwxr-xr-x）？

Question

1- Whenever I try to require anything by the composer in my laravel5 project it doesnt work .. and this error appears

Fatal error: Uncaught exception 'PharException' with message 'phar "/usr/local/bin/composer" has a broken signature' in /usr/local/bin/composer:23

Stack trace:

#0 /usr/local/bin/composer(23): Phar::mapPhar('composer.phar')
#1 {main}

Thrown in /usr/local/bin/composer on line 23

And when I try to move it I got that error

mv composer.phar /usr/local/bin/composer
mv: try to overwrite ‘/usr/local/bin/composer’, overriding mode 0755 (rwxr-xr-x)? 

When I press yes... it is said that access denied

by the way I am using Ubuntu ..

2- when i try to make illuminate/Html it doesnt work too because of the problem oof the composer too