PHP clears file sample code after reading file contents

This article mainly introduced PHP read the file content how to empty the file, the need for friends can refer to the

The code is as follows: $FH = fopen ($path, "r+");    if (Flock ($FH, LOCK_EX)) {//write lock $old _content=json_decode (Fread ($fh, FileSize ($path)), true);  $old _content= $old _content. $new _content; Ftruncate ($fh, 0); Truncates the file to a given length rewind ($FH);  Returns the position of the file pointer fwrite ($FH, Json_encode ($old _content));  @chmod ($path, 0644); Flock ($FH, lock_un); Unlock} fclose ($FH);