How to remove all the spaces and new line and make one single string?

Question

I have following string (using $_POST), how to remove all the new line, spaces and make it as a absolute single line?

Physical Address. . . . . . . . . : E8-6A-64-DE-48-60
Physical Address. . . . . . . . . : 04-EA-56-08-E6-8F
Physical Address. . . . . . . . . : 06-EA-56-08-E6-8E
Physical Address. . . . . . . . . : 04-EA-56-08-E6-8E
Physical Address. . . . . . . . . : 04-EA-56-08-E6-92

Not always stable?

$request= mysql_real_escape_string(trim($_POST['request']));
$request_sql =str_replace("\r\n",'', $request);
$request_sql = str_replace("\\r\\n",'', $request_sql);
echo $request_sql;

You are replacing `\r\n` not `\r` and `\n`. you should call `str_replace` for every character you want to remove. or use a regex — Accountant م, Aug 22 '19 at 07:49
You mean this wont work? ` $request_sql =str_replace("\r\n",'', $request); $request_sql = str_replace("\\r\\n",'', $request_sql); $request_sql = str_replace("\\r",'', $request_sql); $request_sql = str_replace("\\n",'', $request_sql); $request_sql = str_replace("\r",'', $request_sql); $request_sql = str_replace("\n",'', $request_sql);` — , Aug 22 '19 at 07:51
You should use `mysqli_real_escape_string` instead of the `mysql_*` function. This makes it easier to migrate code to php 7.x — LLJ97, Aug 22 '19 at 07:54
This will remove new lines, not spaces. and this `\\n` will remove `\n` (not the new line char but will remove a backslash followed by char n)., the answer by @H.Hamidi should be fine. — Accountant م, Aug 22 '19 at 07:54
You should still use it. It is highly discouraged to use the `mysql_*` extension. The `mysqli_*` is safer. — LLJ97, Aug 22 '19 at 07:55
What is your post data ? This line Physical Address. . . . . . . . . : E8-6A-64-DE-48-60 or only E8-6A-64-DE-48-60 ??? — Salines, Aug 22 '19 at 08:32

score 1 · Answer 1 · answered Aug 22 '19 at 07:52

1

trim only strips spaces at end and start of the string and you should strip \r and \n individually.

try this:

$request= mysql_real_escape_string($_POST['request']);
$request_sql =str_replace("\n",'', $request);
$request_sql = str_replace("\r",'', $request_sql);
$request_sql = str_replace(" ",'', $request_sql);
echo $request_sql;

answered Aug 22 '19 at 07:52

FadedForEver

146
10

SQL injection risks? are there. – Aug 22 '19 at 07:59
I mean just test if there is problem in escaping.yes ,your are right, there is must in escaping strings. – FadedForEver Aug 22 '19 at 08:01
@YumYumYum Why this didn't work ? this should replace every `"\n"` and every `"\r"` and every space from your string, what makes you think it didn't work ? do you have sample data and expected result ? – Accountant م Aug 22 '19 at 08:04
@Accountant م maybe there is problem in encoding string ? – FadedForEver Aug 22 '19 at 08:06
`PhysicalAddress:E8-6A-64-DE-48-60PhysicalAddress:04-EA-56-08-E6-8FPhysicalAddress:06-EA-56-08-E6-8EPhysicalAddress:04-EA-56-08-E6-8EPhysicalAddress:04-EA-56-08-E6-92` - Sample data expected result. – Aug 22 '19 at 08:06
@YumYumYum hey i just made code sample of my code . could you take look at that . https://www.tehplayground.com/xVFZUoHfrijj3uh6 – FadedForEver Aug 22 '19 at 08:08
@YumYumYum hmm, ASCII and UTF-8 will both work fine for finding these 3 chars "\r" and "\n" and space, but I'm not sure about other encodings, sorry. – Accountant م Aug 22 '19 at 08:09
@YumYumYum check [this answer](https://stackoverflow.com/a/3786018/5407848) – Accountant م Aug 22 '19 at 08:15
1

@YumYumYum oh I didn't notice that you are escaping the string before removing the chars you want to remove, **First** remove the chars from the original input, **second**, escape the string, or better use **prepared statements**. – Accountant م Aug 22 '19 at 08:29
@Accountant م i don't it works but it worth testing. – FadedForEver Aug 22 '19 at 08:31

score 1 · Answer 2 · answered Aug 22 '19 at 07:57

1

Try using regex.

$request = $_POST['request'];

//Remove all characters that are not A-Z, a-z, 0-9 or '.', ':' or '-'
$request_sql = preg_replace("/[^A-Za-z0-9.:-]/", '', $request );

answered Aug 22 '19 at 07:57

Enbee

128
9

`E8-6A-64-DE-48-60` from line `: and -` middle dash cant be removed, its part of original value. – Aug 22 '19 at 07:59
`$request_sql = preg_replace("/[^A-Za-z0-9:-]/", '', $request );` did not worked. – Aug 22 '19 at 08:05
It should work unless I am not understanding your question correctly, see [this example](https://ideone.com/HoCJqI). – Enbee Aug 22 '19 at 08:08

score 0 · Answer 3 · answered Aug 22 '19 at 08:35

try:

$str = 'Physical Address. . . . . . . . . : E8-6A-64-DE-48-60 
Physical Address. . . . . . . . . : 04-EA-56-08-E6-8F 
Physical Address. . . . . . . . . : 06-EA-56-08-E6-8E 
Physical Address. . . . . . . . . : 04-EA-56-08-E6-8E 
Physical Address. . . . . . . . . : 04-EA-56-08-E6-92';

echo str_replace(" \n", '', $str);

Output:

Physical Address. . . . . . . . . : E8-6A-64-DE-48-60Physical Address. . . . . . . . . : 04-EA-56-08-E6-8FPhysical Address. . . . . . . . . : 06-EA-56-08-E6-8EPhysical Address. . . . . . . . . : 04-EA-56-08-E6-8EPhysical Address. . . . . . . . . : 04-EA-56-08-E6-92

After replacing the \n you can use mysql escape string to avoid sql injection.

score 0 · Answer 4 · answered Aug 22 '19 at 09:22

The problem with your code is that mysql_real_escape_string will not only escape ' and " but it will escape other characters like \n and \r which you want to remove.

It will replace new line characters with a backslash character followed by l characters

so removing newlines, carriage return after they have been escaped will result in a string with extra backslashes \ and n and r characters.

Check out this

<?php
$originalString = 
"Line1 
Line2
";
// CASE 1 WRONG RESULT
$string1 = mysqli_real_escape_string($con, $originalString);
$string1 = str_replace("\n", '', $string1);

echo "escape then replace result \n";
echo $string1 . "\n";

//CASE 2 EXPECTED RESULT
$string2 = str_replace("\n", '', $originalString);
$string2 = mysqli_real_escape_string($con, $string2);

echo "replace then escape result \n";
echo $string2 . "\n";

this will output

escape then replace result 
Line1\nLine2\n
replace then escape result 
Line1Line2

So to correct your code

$request_sql =str_replace(["\n", "\r", " "],'', $_POST['request']);
$request= mysql_real_escape_string($request_sql);
echo $request_sql;

Please don't use mysql_real_escape_string , instead use prepared statements, here an answer for how to switch to them, they will make your life much more easier and safer.

How to remove all the spaces and new line and make one single string?

4 Answers4