How to read integers separated by space from a file in php - php

I am trying to read a line where multiple numbers were separated by space using php. Initially I tried using fscanf however the issue is, as fscanf read one line at a time, it only reads the first number. I am confused what to do.
Sample Input
20 30 -5987 456 523

The best approach for this case is to use a combination of explode and file reading. The strategy is initially read the whole line as an string. Then use explode to store the all the number in an array. However in that case the array would a string array later on we can change the type of array element from String to integer. Here is how
<?php
$_fp = fopen("php://stdin", "r");
fscanf($_fp, "%d\n", $count);
$numbers = explode(" ", trim(fgets($_fp)));
foreach ($numbers as &$number)
{
$number = intval($number);
}
sort($numbers);
?>

$input = trim(fgets(STDIN));
$arr = explode(" ", $input);
foreach($arr as &$number){
$number = (int)$number;
}

If you want to eliminate white space from "fopen" function user "trim" function or surround variable with trim function.
Example :
echo "Please enter series limit : ";
$handles = fopen ("php://stdin","r");
$n = trim(fgets($handles));
So here we can remove white space in between the characters as well as at the end.

Related

PHP Remove duplicates string on same line of file for all lines?

I apologize for a confusing title. Basically, i'm facing a problem with my website which ends up bugging it completely. I need to basically remove all duplicate entries on the same line, on all lines in my text file list. I.e.
123123
123
123
Sometimes i get entries like 123123 on the same line when it should just be 123, on each line. This is just an example of course, it's hard for me to explain. I apologize again. I hope this was enough for you to gasp what i mean.
To sum it up, i'm need to remove the duplicate part of the string 123123, so it's just 123, for all of the lines in my text file.
Help appreciated.
A live example for this:
2017-06-21:127.0.0.12017-06-21:127.0.0.1
2017-06-21:127.0.0.12017-06-21:127.0.0.1
2017-06-21:127.0.0.12017-06-21:127.0.0.1
2017-06-21:127.0.0.1
$linesStr = '2017-06-21:127.0.0.12017-06-21:127.0.0.1
2017-06-21:127.0.0.12017-06-21:127.0.0.1
2017-06-21:127.0.0.12017-06-21:127.0.0.1
2017-06-21:127.0.0.1';
//can be \n only
$lines = explode("\r\n", $linesStr);
//loop through all lines
foreach($lines as $i => $line)
{
$lineLen = ceil(strlen($line) / 2);
$first = substr($line, 0, $lineLen);
$second = substr($line, $lineLen);
if($first == $second)
{
$lines[$i] = $first;
}
}
$lines = implode("\r\n", $lines);
This should do it...
A basic algorithm to deduplicate a string:
Split it in half.
If the both halves are the same, replace the whole string with either half.
Caveat: this doesn't care whether or not the string was intended to be a duplicate or not, and consequently may remove some things you don't want it to.
function deduplicate($str) {
$str = trim($str);
list($beginning, $end) = str_split($str, strlen($str) / 2);
return ($beginning == $end) ? $end : $str;
}
Assuming you have an array of lines from your file you can apply it with array_map.
$lines = array_map('deduplicate', $lines);

str_split adding empty elements in array end when reading from file

I found interesting problem while I was trying to achieve something simple like splitting string into array. The only difference here is that Im trying to take the string from .txt file
My code is the following:
$handle = fopen("input.txt", "r"); // open txt file
$iter = fgets($handle);
// here on first line I have the number of the strings which I will take. This will be the for loop limitation
for ($m = 0; $m < $iter; $m++)
{
$string = fgets($handle); // now getting the string
$splited = str_split($string); //turn it into array, this is where problem appears
print_r ($splited); // just show the array elements
echo "<br>";
echo count($splited);
echo "<br>";
}
This is the content of my .txt file
4
abc
abcba
abcd
cba
I tried with array_filter() and all other possible solutions/functions. Array filter and array diff are not removing the empty elements, no idea why... Also in my txt file there are no blank spaces or anything like that. Is this a bug in a str_split function ? Any logic behind this ?
The extra whitespace is a newline. Each row except the last technically contains all of the text contents you see, plus a newline.
You can easily get rid of it by e.g.
$string = rtrim(fgets($handle));
Also, fgets($fp); makes no sense since there's no variable $fp, should be fgets($handle); given your above code.
Trimming the spaces and need to change your fgets($fp) to fgets($handle) as there's no variable like of $fp.You need to update your code into as
for ($m=0;$m<$iter;$m++)
{
$string = trim(fgets($handle)); //
$splited = str_split($string); //turn it into array, this is where problem appears
print_r ($splited); // just show the array elements
echo "<br>";
echo count($splited);
echo "<br>";
}

php foreach counting new lines (\n)

If I have a piece of code that works like this:
$i = 0;
$names = explode(",", $userInput);
foreach($names as $name) {
$i++;
}
It works perfectly, provided the user has placed a comma after each name entered into the html textarea this comes from. But I want to make it more user friendly and change it so that each name can be entered on a new line and it'll count how many lines the user has entered to determine the number of names entered into the field. So I tried:
$i = 0;
$names = explode("\n", $userInput);
foreach($names as $name) {
$i++;
}
But this just gives me "1" as a result, regardless the number of new lines in the textarea. How do I make my explode count new lines instead of basing the count on something specifically entered into the text string?
EDIT Thanks to the people who answered, I don't believe there were any wrong answers as such, just one that suited my original code better than the others, and functioned. I ended up adopting this and modifying it so that numerous blank line returns did not result in artificially inflating the $userInput count. Here is what I am now using:
if(($userInput) != NULL) {
$i = 0;
$names = explode(PHP_EOL, trim($userInput));
foreach($names as $name) {
$i++;
}
}
It trims the empty space from the $userInput so that the remainder of the function is performed on only valid line content. :)
Don't make it complicated, you don't have to explode it into an array, just use this:
(Just count the new line character (PHP_EOL) in your string with substr_count())
echo substr_count($userInput, PHP_EOL);
Try using the PHP end of line constant PHP_EOL
$names = explode(PHP_EOL, $userInput);
A blank string as input:
var_dump(explode("\n", ''));
gives this as a result from a call to explode():
array(1) { [0]=> string(0) "" }
so you could use a ternary statement:
$names = $userInput == '' ? array() : explode("\n", $userInput);
Maybe you can change the explode function with preg_split to explode the user string with a regex
$users = preg_split('/[\n\r]+/', $original);
That's the idea, but I'm not on the computer so I can't test my code.
That regex would split the string if it founds one or more line breaks.

Prepend each line of a variable with a string

How can I prepend a string, say 'a' stored in the variable $x to each line of a multi-line string variable using PHP?
Can also use:
echo preg_replace('/^/m', $prefix, $string);
The / are delimiters. The ^ matches the beginning of a string. the m makes it multiline.
demo
There are many ways to achieve this.
One would be:
$multi_line_var = $x.str_replace("\n", "\n".$x, $multi_line_var);
Another would be:
$multi_line_var = explode("\n", $multi_line_var);
foreach($multi_line_var AS &$single_line_var) {
$single_line_var = $x.$single_line_var;
}
$multi_line_var = implode("\n", $multi_line_var);
Or as a deceitfully simple onliner:
$multi_line_var = $x.implode("\n".$x, explode("\n", $multi_line_var));
The second one is dreadfully wasteful compared to the first. It allocates memory for an array of strings. It runs over each array item and modifies it. And the glues the pieces back together.
But it can be useful if one concatenation is not the only alteration you're doing to those lines of text.
Because of your each line requirement, I would first split the string to an array using explode, then loop through the array and add text to the beginning of each line, and then turn the array back to a string using implode. As long as the number of lines is not very big, this can be a suitable solution.
Code sample:
$arr = explode("\n", $x);
foreach ($arr as $key => $value) {
$arr[$key] = 'a' . $arr[$key];
}
$x = implode("\n", $arr);
Example at: http://codepad.org/0WpJ41LE

How can we split a sentence

I have written the PHP code for getting some part of a given dynamic sentence, e.g. "this is a test sentence":
substr($sentence,0,12);
I get the output:
this is a te
But i need it stop as a full word instead of splitting a word:
this is a
How can I do that, remembering that $sentence isn't a fixed string (it could be anything)?
use wordwrap
If you're using PHP4, you can simply use split:
$resultArray = split($sentence, " ");
Every element of the array will be one word. Be careful with punctuation though.
explode would be the recommended method in PHP5:
$resultArray = explode(" ", $sentence);
first. use explode on space. Then, count each part + the total assembled string and if it doesn't go over the limit you concat it onto the string with a space.
Try using explode() function.
In your case:
$expl = explode(" ",$sentence);
You'll get your sentence in an array. First word will be $expl[0], second - $expl[1] and so on. To print it out on the screen use:
$n = 10 //words to print
for ($i=0;$i<=$n;$i++) {
print $expl[$i]." ";
}
Create a function that you can re-use at any time. This will look for the last space if the given string's length is greater than the amount of characters you want to trim.
function niceTrim($str, $trimLen) {
$strLen = strlen($str);
if ($strLen > $trimLen) {
$trimStr = substr($str, 0, $trimLen);
return substr($trimStr, 0, strrpos($trimStr, ' '));
}
return $str;
}
$sentence = "this is a test sentence";
echo niceTrim($sentence, 12);
This will print
this is a
as required.
Hope this is the solution you are looking for!
this is just psudo code not php,
char[] sentence="your_sentence";
string new_constructed_sentence="";
string word="";
for(i=0;i<your_limit;i++){
character=sentence[i];
if(character==' ') {new_constructed_sentence+=word;word="";continue}
word+=character;
}
new_constructed_sentence is what you want!!!

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