[SOLVED] PHP Session variable value doesn't retrieved to another page

Q. PHP Session variable value is not transfering?

So, you are having trouble with php session variables! Well, Let see how can it being solved! If you didn't read about PHP Session variables then have a look on the manual!

Well let see what is happening...

PHP file: <test1.php>

<?PHP
session_start();

header("Access-Control-Allow-Origin: *"); 
header("Content-Type: application/json; charset=UTF-8");

//some code to determine $approvedToSet
$approvedToSet = true;
if(isset($approvedToSet))
{
$_SESSION["userName"] = 'MyName'; 
echo " Session variable is set." .$_SESSION["userName"];
} 
else { 
echo "User name is not set";} 

?>

PHP file: <test2.php>

<?PHP
echo $_SESSION["userName"];

ERROR:

Notice: Undefined index: userName in /var/www/xyz on line 30



[Solution:]

Correct Your file and ensure session_start(); function is on the top of your page.

PHP file: <test2.php>

<?PHP
session_start()
echo $_SESSION["userName"]; ?>

1. Stop your apache2 or http server and start it again!
2. Ensure session.save_path has been set.
3. Must be Make sure session_start(); is called before any sessions are being called. So a safe bet would be to put it at the beginning of your page, immediately after the opening <?php tag before anything else. Also ensure there are no whitespaces/tabs before the opening <?phptag.
4. After the header redirect, end the current script using exit(); (Others have also suggestedsession_write_close(); and session_regenerate_id(true), you can try those as well, but I'd use exit();).
5. Make sure cookies are enabled in the browser you are using to test it on.
6. Ensure register_globals is off, you can check this on the php.ini file and also using phpinfo(). Refer to this as to how to turn it off.
7. Make sure you didn't delete or empty the session.
8. Make sure the key in your $_SESSION superglobal array is not overwritten anywhere.
9. Make sure you redirect to the same domain. So redirecting from a www.yourdomain.com to yourdomain.com doesn't carry the session forward.
10. Make sure your file extension is .php (it happens!).
11. If you use a connection script, dont forget to use start_session(); at the connection too, had some trouble before noticing that issue.

iu

Tags: coding → debugging → error → novice coding → novice debug → php concept → solution

[SOLVED] PHP Session variable value doesn't retrieved to another page

By Game Changer → Friday, May 5, 2017

[Solved] PHP fopen() Error: failed to open stream: Permission denied

Finally You have fethed the error. Is it?

Warning: fopen(/path/to/file.ext) [function.fopen]: failed to open stream: Permission denied

NOTE: You are opening a file. Make sure the correct file permissions you have.

In Ubuntu the php user group is www-data:www-data and for centos is apache:apache
- Ensure your user www-data is a member of root

adduser www-data root

Then use this command in terminal
chmod g+rw /path/to/file/



Try with php fopen again:

$myFilePath = "/path/to/file.ext";
$file_handle = fopen( $myFilePath, 'r+' );

Also! You can chmod 775 for you directory.
chmod 0775 /path/to/file/

Check the followings:

• The directory has the correct file permissions (755) and the correct ownership. This is true all the way up the path to /home.
• Ensure correct directory as confirmed by getcwd()
• The test PHP script hash the same ownership as the path trying to write to and correct permission (644).
• PHP safe mode is disabled in php.ini.
• fopen is not a disallowed PHP function.
• The use of open_basedir is disabled.
• A parent directory has the wrong permissons.

Yet Not?

Remember that in order to reach a file, ALL parent directories must be readable by www-data. You strace output seems to indicate that even accessing /var/log/apache2/writetest is failing. Make sure that www-data has permissions on the following directories:

• / (r-x)
• /var (r-x)
• /var/log (r-x)
• /var/log/apache2 (r-x)
• /var/log/apache2/writetest (rwx)
• /var/log/apache2/writetest/writetest.log (rw-)

Yet Not Again?

Could be a SELinux issue, even if Debian doesn't ship it in the default installation your provider could have enabled it. Look for messages in /var/log with

grep -i selinux /var/log/{syslog,messages}

If that's the cause and you need to disable it, here are instructions: look for file /etc/selinux/config, here it's default content. Change SELINUX directive to disabled and reboot the system.

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#   enforcing - SELinux security policy is enforced.
#   permissive - SELinux prints warnings instead of enforcing.
#   disabled - SELinux is fully disabled.
SELINUX=disabled
# SELINUXTYPE= type of policy in use. Possible values are:
#   targeted - Only targeted network daemons are protected.
#   strict - Full SELinux protection.
SELINUXTYPE=targeted

Tags: coding → debugging → error

[Solved] PHP fopen() Error: failed to open stream: Permission denied

By Game Changer → Monday, December 7, 2015

URLENCODE vs RAWURLENCODE

Differences in ASCII:

URLENCODE:

• Calculates a start/end length of the input string, allocates memory
• Walks through a while-loop, increments until we reach the end of the string
• Grabs the present character
• If the character is equal to ASCII Char 0x20 (ie, a "space"), add a + sign to the output string.
• If it's not a space, and it's also not alphanumeric (isalnum(c)), and also isn't and _, -, or .character, then we , output a % sign to array position 0, do an array look up to the hexcharsarray for a lookup for os_toascii array (an array from Apache that translates char to hex code) for the key of c (the present character), we then bitwise shift right by 4, assign that value to the character 1, and to position 2 we assign the same lookup, except we preform a logical and to see if the value is 15 (0xF), and return a 1 in that case, or a 0 otherwise. At the end, you'll end up with something encoded.
• If it ends up it's not a space, it's alphanumeric or one of the _-. chars, it outputs exactly what it is.

RAWURLENCODE:

• Allocates memory for the string
• Iterates over it based on length provided in function call (not calculated in function as with URLENCODE).

Note: Many programmers have probably never seen a for loop iterate this way, it's somewhat hackish and not the standard convention used with most for-loops, pay attention, it assigns x and y, checks for exit on len reaching 0, and increments both x and y. I know, it's not what you'd expect, but it's valid code.

• Assigns the present character to a matching character position in str.
• It checks if the present character is alphanumeric, or one of the _-. chars, and if it isn't, we do almost the same assignment as with URLENCODE where it preforms lookups, however, we increment differently, using y++ rather than to[1], this is because the strings are being built in different ways, but reach the same goal at the end anyway.
• When the loop's done and the length's gone, It actually terminates the string, assigning the \0byte.
• It returns the encoded string.

Differences:

• UrlEncode checks for space, assigns a + sign, RawURLEncode does not.
• UrlEncode does not assign a \0 byte to the string, RawUrlEncode does (this may be a moot point)
• They iterate differntly, one may be prone to overflow with malformed strings, I'm merely suggesting this and I haven't actually investigated.

They basically iterate differently, one assigns a + sign in the event of ASCII 20.

Differences in EBCDIC:

URLENCODE:

• Same iteration setup as with ASCII
• Still translating the "space" character to a + sign. Note-- I think this needs to be compiled in EBCDIC or you'll end up with a bug? Can someone edit and confirm this?
• It checks if the present char is a char before 0, with the exception of being a . or -, OR less than A but greater than char 9, OR greater than Z and less than a but not a _. OR greater than z (yeah, EBCDIC is kinda messed up to work with). If it matches any of those, do a similar lookup as found in the ASCII version (it just doesn't require a lookup in os_toascii).

RAWURLENCODE:

• Same iteration setup as with ASCII
• Same check as described in the EBCDIC version of URL Encode, with the exception that if it's greater than z, it excludes ~ from the URL encode.
• Same assignment as the ASCII RawUrlEncode
• Still appending the \0 byte to the string before return.

Grand Summary

• Both use the same hexchars lookup table
• URIEncode doesn't terminate a string with \0, raw does.
• If you're working in EBCDIC I'd suggest using RawUrlEncode, as it manages the ~ that UrlEncode does not (this is a reported issue). It's worth noting that ASCII and EBCDIC 0x20 are both spaces.
• They iterate differently, one may be faster, one may be prone to memory or string based exploits.
• URIEncode makes a space into +, RawUrlEncode makes a space into %20 via array lookups.

Disclaimer: I haven't touched C in years, and I haven't looked at EBCDIC in a really really long time. If I'm wrong somewhere, let me know.

Tags: advanced php → best coding → choice → debugging

URLENCODE vs RAWURLENCODE

By Game Changer → Saturday, December 5, 2015