Home > Article > Backend Development > Application skills of various functions in PHP file operations_PHP tutorial
1. Open file: fopen("file name", "mode");
Mode:
r :read-only
r+:read/write
w:write-only. Open and clear the contents of the file. If the file does not exist, the file is created.
w+: read/write. Open and clear the contents of the file. If the file does not exist, create the file.
a: Append. Open and write to the end of the file. If the file does not exist, a new file is created.
a+: read/append. Maintain file contents by writing to the end of the file.
2. Close the file: fclose();
For example:
<ol class="dp-xml"><li class="alt"><span><span class="tag"><</span><span> ? </span></span></li><li><span>$</span><span class="attribute">file</span><span>=</span><span class="attribute-value">fopen</span><span>("test.txt","r"); </span></li><li class="alt"><span>//some code be executed </span></li><li><span class="attribute">fclose</span><span>=($file); </span></li><li class="alt"><span class="tag">?></span><span> </span></span></li></ol>
3. Check whether the end of the file has been reached: feof( );
For example: if(feof($file)){ echo "end of file";}
4. Read the file line by line: fgets();
For example:
<ol class="dp-xml"> <li class="alt"><span><span>$</span><span class="attribute">file</span><span>=</span><span class="attribute-value">fopen</span><span>("test.txt","r"); </span></span></li> <li><span>while(!feof($file)){ </span></li> <li class="alt"> <span>echo fgets($file)."</span><span class="tag"><</span><span> </span><span class="tag-name">br</span><span class="tag">/></span><span>"; </span> </li> <li><span>} </span></li> <li class="alt"><span>fclose($file); </span></li> </ol>
5. Read the file character by character: fgetc()
6. Whether the file exists: file_exists(); returns true if it exists, Otherwise, return false
7. Read the file into an array: $array=file("text.txt"), $array[0] is the first line of text, and so on. If you want to flip the entire array, for example:
$arr=array_reverse($array);
The last line of text is $arr[0].
Get the array $array If the number of rows in the text database is $num=count($array);
to determine if the text database is not empty, use: if($num>0){}
to calculate the total pages Number: $total=ceil($num/$pagesize) $pagesize is the number of information displayed on each page.
Calculate the first record number displayed on the current page: $number=($page-1)*$pagesize;
Use " " as the separator to separate each record in the array $arr $number units of data, and assign these data to the array $rom
for($i=0;$i<=$pagesize-1;$i++){$row=explode(" ",$ arr[$number];}
Assign the unit data in the data row to the variables in the brackets in order
list($ip,$datetime,$name,$email,$home) =$row