Replacing with preg_replace

Question

I have an SVG file that has a bunch of base64 encoded images inline. I want to replace this data with the paths to these images instead.

Path of SVG that shows base64 encoded data:

<image overflow="visible" width="960" height="720" id="Layer_0_1_" xlink:href="
data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAA8EAAALRCAYAAAB76aEvAAAACXBIWXMAAB
KbAAASmwHgklkMAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAIiDZJREFUeNrsvQu
WIzmuLEi6FPmp6nl3ljJbnJXNVmYB75zpvn2rsjJDco5AEqQRDpB0uRQRWZ2qVitSH//wCwMMBv/1
85f/0zn3f7nOw3vv7n3Qb0e/P3J8eoQQDp3/6O+fffyjj975nadrCO69+19eI/7u+/fv7q+//nK
vrxfnfb0eej2/" />

I have the following PHP code so far:

$content = preg_replace('/"data:image\/png;base64(.*)"/', '"pathtologo.png"', $content);

I realize there must me something wrong with the (.*) as it is not replacing anything.

Can anyone offer any help on this matter? Regex has never been my strong suit.

After the replace, I'm expecting:

<image overflow="visible" width="960" height="720" id="Layer_0_1_" xlink:href="
pathtologo.png" />

A small excerpt of the base64 data that is not working with the regex answers provided below:

iVBORw0KGgoAAAANSUhEUgAAA8EAAALRCAYAAAB76aEvAAAACXBIWXMAABKbAAASmwHgklkMAAAA GXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAIiDZJREFUeNrsvQuWIzmuLEi6FPmp 6nl3ljJbnJXNVmYB75zpvn2rsjJDco5AEqQRDpB0uRQRWZ2qVitSH//wCwMMBv/185f/0zn3f7nO w3vv7n3Qb0e/P3J8eoQQDp3/6O+fffyjj975nadrCO69+19eI/7u+/fv7q+//nKvrxfnfb0eej2/ vLjff/8/3LIs8cm/o+Ot69q/99vj9g13vV5vr/vasrzezuGua/f7r6+vnc9v13D1B/pvdan7VrNt T6dTbAv+m18/ffp0e744vzj3cmtHaj/+HrcxtyG1Eb3S+/Q33VP67u3HwTd9Itup3we3fgpX8/f0 oOsajS/ZL/J4d7evGIva9eF4oyf+hscltyu1Mz3rb27tQ0OIxmBu6x8/fsTxfrlczOvj42tz5y0f o/nN7TJaf7DfuK1ofH758sWdz2ez/bn9sA/4O9R+9KSxjuMXxxX3Bf3u21/fYrufT2f39evXeF76 HR2D+5HnD88N+ozmQlyLbt/n49GDvstzj+cL9j8dm69LG1PYhvhdng90zOt6iXOIzvP58+fYZvJY +BseZ7gWYJvykz+nc9B45Puhe+R7onu/ffP273M5Fq8N9Bv6HPte3lNeQOP104OO/dtvv5W2l2sH zy++h/i8BieHf/lMrP88H+nY1FY0tmj5Wter2ma4/vG9xXvO14VzFvsQxyo+rbnRnR+D9YnHZR0j a9wjaRxwO2rHqfPttme6pfQnP3Ef4LHNTxwvl+tt/N++z+MTx7O1b2L7nJbbmBLj0LI/rNc9tots g9H6JD/f7DNLXMC6Y693nZ5aP881euJeN/P7EPfPcGh/e+bnR/ff4f4x8Xuc+3vbd+b+j9oXz/z9 I+yfZ+KPD3B9/+85A+D/x/16/Hr8jI/gysaLxh4adF0QHI6B4IRi+5to/xoOOEA8/3r/JvWewGlk 5PyUw9AwhB/R1hLoSsP6SLu9xTjoX1/ofu9R1zfjiOT/5LXI69L6VgOy2hokx8lsO2mfJfCzkBnc BRuW82SPk0NzasVjBPe3fuxpJwnwZgz0mfG9Z34/awmV46qO7fddc/cAGO3vUR9YvxmtK3I8PK8N jo3h0TU+AsAdOf5HslN+Pf6Wj//7/He4i16k6GfaSH899htl5CWk6I309M2C4BipvV76tlw09kI1 2dEgSEj6yB05v5xsMBx6ODlko93+EhpjcmOO7XN7PeV2w3kk29E2qN1BQ8ir83d2zryFobHLKSKu q9d2/BuO5PB45rEsgZgWZXrEfHq2p7q3PkdPf7hs5vcOP5A5d61j4T1zxJmilwvMAxkxxrUE5wb2 izSs8Ry4bpHTDft6NqLFEWt6cOToel3c5ZqYJnRcGX2Ux0e2jBZZ4+Pz9zj6y1FPvr9yHMHAsdrw Ees9nqP+223WtEfMBf4b+xqdrZpDQYvkS3aINmdGzo/R/JHriGTxYP/K+xutuZZTp573sSBFi9zK +bUXRPUiuXvXt63Tiy66jShiP8w6OvbYjps+ce/HNJxi263r0/aWvevIz2ibP/san8nE/Rke5/fu gLfoxBm6473H/tkBrv8J+r+3kEca1/WHapBMTc47gxkBQPFysI3Sz0PHyu9Hkr3z+64ZjRgwLi3D +Ll9Oz5HbxP9COOzF20Yrh+KwcsAAsGxdc/vff+zjqbOp40RzwY/0ky1sViM4gyEes6BHuBgqifS qCWIayNfoQFmeM3SOYfGMFId94BfbBsENwxO6S1KJ0CqMF8LA2XpkGDq8iaqKxwy/G+mJl8y7bW5 JgGqRxRg3cFY1z85nvA40vkQ3/fhkIMnrp7CUSjPwekMvfFuOcEsR5gEpPfOH+08/MpzSLZb87uO 81SO+3sA5MQKsptB05vfe9bne2y8TbqPYkTta5+tA7s3VrTxN4q0zka67wG5M23/CCbUM2z7X49f jwiC78mr+GiPZ0+Enx0Id6/PjylU731/1aiyF+p7QXD8/uIPtaN3H9eTNgIFCQcHFSTL+5ZAY/a6 R+MPDeD3GHePPI8VETQNYcqHXcMu40FGRo7SoY+Mv6MgOEUxwpDibdFMfQZSGgieiQRrRj5G4jEK jDmcDCwIUFKOL4NDBqHy2JgbjiB1NlIor6NpA2XtwyggnxfvyTJwZeRNRnf5N2XNdTZdf++4stYd PQJpg5Rd5/dp/dYAonQ+zDgXtTGGThINvI6c8DOR4s28EA416/5yD06v7Y9m3sTxtOptMRstn82Z dsZYPbRnZB+OzCGfiZDu2Y/QqdGsAQoIl+17JKf22fbJ6PiP1rz42UDxI673aE7ue46NNwHBf7dB 89aD8Fck+O36YCSc0TNIbCM8i1vduzk5NxSmeCZd309et2aI9YCVNHZM8TIyIB+0EWqRqREd8COu F3upe73okkb1fCQt+hGe+mPHD80gnt2wS5vklAANNGvAQHMIodASGrBsQLNAGRuVDHQxyqu9TxFU plnT31pkH+elXMdkhFxLbaC24ygzAlUZubTWSEl/1hyL/DlGkPk7yzIW9eoLA2UgEfbNkx5gfvQ+ r40fjS49cgRofSDTULS9Q0bze+u71Ybm/YW+M+G9Rfesa+/NaesY99Kpe7aEFKZCZ1nDWJg8x2jP lWJea1ifLoz17EjsW9iYbyFA+6z985maH++dTvYhQPDfIRL87Os/CoRHnrh35fz/BJFguZk1m4NP dOQgJ3z5284aDOV4kyDLQ9QXXsIoJ3hEZ/bu/s+DG15/j+5soeiew2HveBh/v69+/N7rwyyjQAUp BhCpf9fxOQNsH01JfEbO2q6+j5+vXfGlkbpqMPpB5tFa945AkB7XNancMriU1HQGxTK6y2s9/hs/ lxRrCS4RyGAkCYEyA6J6X/Te0uTpairlVsRw1oiS0egR2JuetzmazCJLVjR11gmqUbK7jhWxAVr5 xZgfLY/bywm22A17coJn6K4brQdj/mzuz/MeooMvrW0fu/Yucf+28qutnOvZa5Lz8UhOsDYe41oB qRSPEMTSfivvoTzdY4XV7vntM5mYo/1pL36x9uiPDoR/5uN/eBD8s9/AIxbmZxrav9TtHte/ViSW NlIWeQoAfmfyWoPfq74pjgnCGPc+RpHOR4xv6ZUe5fHtoZQeuzYX8wqlgMmeCPB7z7FeDtfU/Stt L6NwR/Ky3ttJONUIzmYDaPOuGDEiEtwrR2OBIsyfZRCJJZVkhJWfGIHlvzF3FkXO5H0hdVoz8mXU E8ssIThP4lStQj5eN96fJpikrQ1av2rUfpm/LsH9I8SxpGgX5lmnv9djwnzg2LQow9JZIcfRTO6+ BYL3CjvNggVJw7fvLz17qRX9FIOjtlObE6uxFkYKzbNOgnvWS80Z26xFNA5PweyLvU7GGWdqc0/+ OMh89vr/EfN2fxYA/J8O0P82IPjogPvZKcmP9GTNHvseYPcRnQiWYVvHlC+eZCtfrKcKyHSm2T7a HH/i+kd0tqNti/dufR8BZbOhu1Yxlq5V85JadFPZbPuNjRrpvleYa+/a8ozxOgOE7bxVPWL3kQSw HrH+qffAviQQR1pjjqCbUuENYTsHrTXAihgynTnOkRwZkyJYVj1dnt94bK6viyAX+xbBDYKVbfmZ SjvGGrWWg0iCJXleGbVWhaYGIBiPm9pr67jZNR+hA9XhIfoMHQrsZJDRMI3yfu8+i20jnQ9WuoJ0

Answer 1

You may want to try this:

<?php
$html = <<< EOF
<image overflow="visible" width="960" height="720" id="Layer_0_1_" xlink:href="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAA8EAAALRCAYAAAB76aEvAAAACXBIWXMAABKbAAASmwHgklkMAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAIiDZJREFUeNrsvQuWIzmuLEi6FPmp6nl3ljJbnJXNVmYB75zpvn2rsjJDco5AEqQRDpB0uRQRWZ2qVitSH//wCwMMBv/185f/0zn3f7nOw3vv7n3Qb0e/P3J8eoQQDp3/6O+fffyjj975nadrCO69+19eI/7u+/fv7q+//nKvrxfnfb0eej2/" />
EOF;

$newimage = preg_replace('%"(data:image\/png;base64.*)"%sim', '"pathtologo.png"', $html);
echo $newimage ;
?>

DEMO:
http://ideone.com/E8wwAX

EXPLANATION:

Options: Case insensitive; Exact spacing; Dot matches line breaks; ^$ match at line breaks; Greedy quantifiers; Regex syntax only

Match the character “"” literally «"»
Match the regex below and capture its match into backreference number 1 «(data:image\/png;base64.*?)»
   Match the character string “data:image” literally (case insensitive) «data:image»
   Match the character “/” literally «\/»
   Match the character string “png;base64” literally (case insensitive) «png;base64»
   Match any single character «.*?»
      Between zero and unlimited times, as few times as possible, expanding as needed (lazy) «*?»
Match the character “"” literally «"»

"pathtologo.png"

Insert the character string “"pathtologo.png"” literally «"pathtologo.png"»

Answer 2

My theory of why it's not working properly is because the dot (.) is matching everything except the newline character \n, I would suggest using the s modifier allowing the dot to match newlines, or use negation.

Also you may want to add the ? quantifier after .* for a non-greedy match.

$content = preg_replace('~"data:image/png;base64.*"~s', '"pathtologo.png"', $content);