PHP golfing tips: Reading/writing files and the CLI

You can read a line from STDIN in 13 characters:

fgets(STDIN);

as seen here.

Reading from a file:

file('filename')

returns an array of lines of the file.

Using fputs instead of fwrite will save a character on writing, but I can't think of a shorter way than:

fputs(fopen('filename','w')); //use 'a' if you're appending to a file instead of overwriting

which is marginally shorter than:

file_put_contents('filename');

Depending on the input format, fgetcsv and fscanf can often be byte savers as well.

For example, assume each line of your input consists of two space separated integers. To read these values into an array, you could use one of:

$x=split(' ',fgets(STDIN)); // 27 bytes
$x=fgetcsv(STDIN,0,' ');    // 24 bytes
$x=fscanf(STDIN,'%d%d');    // 24 bytes

Or if you wanted to read each of them into a different variable:

list($a,$b)=split(' ',fgets(STDIN)); // 36 bytes
list($a,$b)=fgetcsv(STDIN,0,' ');    // 33 bytes
fscanf(STDIN,'%d%d',$a,$b);          // 27 bytes