PHP 4.0 Bug #3449: Form method POST doesn't work properly

From: heep@cnetworks.net Operating system: FreeBSD 2.2.8-STABLE PHP version: 4.0 Latest CVS (10/02/2000) PHP Bug Type: Scripting Engine problem Bug description: Form method POST doesn't work properly <hr> Script "post.php3" which illustrate the problem <? echo "<HTML><TITLE>Post Method Test</TITLE>"; echo "<BODY>"; echo "<FORM name=test action=post.php3 METHOD=POST>"; if ($act==''){ $file = fopen("test.txt", "r"); if (!$file) { echo "<p>Unable to open remote file.\n"; exit; } while (!feof($file)) { $tx = fgets($file, 1024); $txt=$txt.$tx; } $txt=addslashes($txt); fclose($file); $lgth=strlen($txt); echo "<BR>Read: length=$lgth"; echo "<hr>"; } if ($act=='post'){ $lgth=strlen($txt); echo "<BR>Read: length=$lgth"; } echo "<BR>act=$act"; echo "<BR><INPUT type=hidden name=act value=post>"; echo "<BR><TEXTAREA rows=10 cols=50 name='txt' align=top >$txt</TEXTAREA>"; echo "<BR><INPUT type=submit value='Send'>"; echo "<INPUT type=reset value='Clear'>"; echo "</FORM>"; echo "</BODY>"; echo "</HTML>"; ?> <hr> Error description: When I send long enough text from the form text area, it cutted somewhere in the middle and last character is "%". It is also clear that if string echo "<BR><INPUT type=hidden name=act value=post>"; will be set after string echo "<INPUT type=reset value='Clear'>"; than value of $act will be empty. To my view there is overwriting some internal buffer in PHP occures when variable filled up by content of POST All works Ok with PHP 3.0 file which I use can be almost any or you can type content of the form by hand (but how much characters I don't know, suppose few kilobytes :) I get content for file from PHP help system. <hr> test file "text.txt" and its content: LII. String functions These functions all manipulate strings in various ways. Some more specialized sections can be found in the regular expression and URL handling sections. Table of Contents AddCSlashes — Quote string with slashes in a C style AddSlashes — Quote string with slashes bin2hex — Convert binary data into hexadecimal representation Chop — remove trailing whitespace Chr — Return a specific character chunk_split — Split a string into smaller chunks convert_cyr_string — Convert from one Cyrillic character set to another crypt — DES-encrypt a string echo — Output one or more strings explode — Split a string by string flush — Flush the output buffer get_html_translation_table — Returns the translation table used by htmlspecialchars() and htmlentities() get_meta_tags — Extracts all meta tag content attributes from a file and returns an array htmlentities — Convert all applicable characters to HTML entities htmlspecialchars — Convert special characters to HTML entities implode — Join array elements with a string join — Join array elements with a string ltrim — Strip whitespace from the beginning of a string md5 — Calculate the md5 hash of a string Metaphone — Calculate the metaphone key of a string nl2br — Converts newlines to HTML line breaks. Ord — Return ASCII value of character parse_str — Parses the string into variables print — Output a string printf — output a formatted string quoted_printable_decode — Convert a quoted-printable string to an 8 bit string QuoteMeta — quote meta characters rawurldecode — Decode URL-encoded strings rawurlencode — URL-encode according to RFC1738 setlocale — Set locale information similar_text — Calculate the similarity between two strings soundex — Calculate the soundex key of a string sprintf — Return a formatted string strcasecmp — Binary safe case-insensitive string comparison strchr — Find the first occurrence of a character. strcmp — Binary safe string comparison strcspn — Find length of initial segment not matching mask strip_tags — Strip HTML and PHP tags from a string StripCSlashes — un-quote string quoted with addcslashes StripSlashes — Un-quote string quoted with addslashes stristr — Case-insensitive strstr() strlen — Get string length strpos — Find position of first occurrence of a string strrchr — Find the last occurrence of a character in a string str_repeat — Repeat a string strrev — Reverse a string strrpos — Find position of last occurrence of a char in a string strspn — Find length of initial segment matching mask strstr — Find first occurrence of a string. strtok — Tokenize string strtolower — Make a string lowercase strtoupper — Make a string uppercase str_replace — Replace all occurrences of needle in haystack with str strtr — Translate certain characters substr — Return part of a string substr_replace — Replace text within a portion of a string. trim — Strip whitespace from the beginning and end of a string ucfirst — Make a string's first character uppercase ucwords — Uppercase the first character of each word in a string User Contributed Notes: String functions Manuel@Hossfeld.de 19-Mar-1999 06:03 One important thing to be aware of when dealing with strings is the meaning of special character sequences and the difference between using <I>single quotes</I> and <I>double quotes</I>. A "normal" string assignment looks like this: $str = "Some string..."; As you probably already noticed elsewhere in this manual you could also use $name = "Joe"; $str = "Hello $name"; // results in "Hello Joe" Now it gets a bit tricky: If your string contains certain special character sequences beginning with a backslash (often referred to as "escape sequences" or "control codes" or similar), PHP will evaluate them and act accordingly. The most useful control codes are \t and \n. \t results in a "TAB", while \n inserts a newline. So... echo "Hello $name\nWelcome to\twonderland" Will give something like Hello Joe Welcome to wonderland (Naturally, it won't show up this way in your browser unless its inside a &lt;PRE&gt; &lt;/PRE&gt; block.) Of course, if you already know any other language like C or JAVA, all this won't tell you anything new. There is a pitfall however, that when e.g. you want to store Windows paths in a string and/or output it the behavior above may bite you. Example: $win_path = "c:\test\mytext.txt"; echo $win_path; This will look like c: est\mytext.txt in the HTML code PHP generates, because it really means "c:(TAB)\mytext.txt"! Since this is probably not what you intended, you should use single quotes in this case: $win_path = 'c:\test\mytext.txt'; The single quotes will ensure that PHP treats this string verbatim, so the \t in this example wouldn't result in a TAB. Be aware that this also prevents PHP from expanding any variables, so echo 'Hello $name'; // this outputs Hello $name ! doesn't work as you might expect. Another means of preventing special character sequences from being evaluated is "escaping" them. (BTW: This concept is also found in many other languages.) What does this mean? In the above example we could've also written: $win_path = "c:\\test\mytext.txt"; echo $win_path; // outputs c:\test\mytext.txt This effectively tells PHP not to interpret the \t as a TAB. Accordingly, the same goes for \\n etc. Now you may ask "Argh, do I have to really take care of this myself - Why can't PHP do it for me?" The answer is yes, it can: Just use the <I>addslashes()</I> function. If you want to know more about it, read the appropriate section. improv@magma.ca 19-Aug-1999 10:08 two functions missing from this list: // Function: rpad // *********************************** // Purpose: right pad a string to a specified length, // or trim it to that length if too long // Inputs: $inStr - String to be padded // $len - length of desired out put string // $with - [optional] character(s) to use in padding // (defaults to space " ") // To Do: improper input error handling // *********************************** function rpad($inStr, $len, $with = " ") { // if inStr needs padding if (strlen($inStr) &lt; $len) { $outStr = $inStr; // output string // make sure $inStr + $with isn't longer than $len if ((strlen($inStr) + strlen($with)) < $len) { // add $with as many times as it will fit for ($i=strlen($inStr);$i&lt;$len;$i+=strlen($with)) { $outStr .= $with; } } // if its still not long enough if (strlen($outStr) != $len) { // tack on a enough of $with to make up the difference $outStr .= substr($with,0,($len-strlen($outStr))); } // off to the races return $outStr; } else { // shrink it down return substr($inStr,0,$len); } } // Function: lpad // *********************************** // Purpose: left pad a string to a specified length, // or trim it from the right to that length // if too long // Inputs: $inStr - String to be padded // $len - length of desired out put string // $with - [optional] character(s) to use in padding // (defaults to space " ") // To Do: improper input error handling // *********************************** function lpad($inStr, $len, $with = " ") { // if inStr needs padding if (strlen($inStr) &lt; $len) { $rStr = $inStr; // the string to be padded $lStr = ""; // the padding // make sure $inStr + $with isn't longer than $len if ((strlen($inStr) + strlen($with)) < $len) { // add $with to the padding as many times as it will fit for ($i=strlen($inStr);$i&lt;$len;$i+=strlen($with)) { $lStr .= $with; } } // stick the values together $outStr = $lStr . $rStr; // if its still not long enough if (strlen($outStr) != $len) { // tack on a enough of $with to the middle to make up the difference $outStr = $lStr . substr($with,0,($len-strlen($outStr))) . $rStr; } // off to the races return $outStr; } // $inStr too long else { // shrink it down (chopping off the left most chars.) return substr($inStr,-$len); } } kris@mha.ca 21-Sep-1999 07:09 lpad and rpad are unnecssary as <A HREF="http://www.php.net/manual/function.sprintf.php3">sprintf<A> will do all that and much more... Kris zarkdav+php@eddy.easynet.fr 08-Oct-1999 02:10 How do you pad a string with n characters using sprintf? I tried the single-quote ' modifier, with no result. ptomblin@xcski.com 12-Oct-1999 05:10 How do I word wrap some text? I get some text in from a text area on a form, and it's nicely word wrapped on the screen. But as soon I go to email it to somebody, it's all one big long text string with no returns. It would be nice if there was a function similar to the unix command "fmt". waltb@rocketcash.com 08-Nov-1999 02:11 How can I upper case an entire string? This is useful when preparing a string for database access, where converting the string in the db query hinders performance. ptomblin@xcski.com 12-Nov-1999 11:11 A quick and dirty function to wrap text at a given wrap margin: function wraptext($text, $wrapmargin) { $rettext = ""; $linebuf = ""; $linelen = 0; $tok = split("[ \t]", $text); $numtok = count($tok); for ($i = 0; $i < $numtok; $i++) { $elem = $tok[$i]; $elemlength = strlen($elem) + 1; if ($linelen + $elemlength > $wrapmargin) { $rettext = $rettext . $linebuf . "\n"; $linebuf = ""; $linelen = 0; } // Do we have a newline in this element? $pos = strrpos($elem, "\n"); if ($pos) { $before = substr($elem, 0, $pos); $after = substr($elem, $pos); $rettext = $rettext . $linebuf . " " . $before . "\n"; $linebuf = $after; $linelen = strlen($after); } else { $linebuf = $linebuf . " " . $elem; $linelen = $linelen + $elemlength; } } // Do we have a newline in this element? $pos = strrpos($elem, "\n"); if ($pos) { $before = substr($elem, 0, $pos); $after = substr($elem, $pos); $rettext = $rettext . $linebuf . " " . $before . "\n"; $linebuf = $after; $linelen = strlen($after); } else { $linebuf = $linebuf . " " . $elem; $linelen = $linelen + $elemlength; } } return $rettext; } fgmp@yahoo.com 16-Jan-2000 05:01 Is there a way to print huge chunks of html without having the escape every damn double quote? I can do this in perl with print qq( ALL THE HTML TAGS YOU CAN THINK OF WITH UNESCAPED QUOTES ); Is ther something simillar to qq(); in php? elliot@rightnowtech.com 27-Jan-2000 07:01 to fgmp@yahoo.com: you should break out of php for large bits of html. not only is it easier, but much much faster compared to echoing or printfing everything. and &lt;? } ?> is perfectly acceptable to php as well.