How can I run sed to replace lines in a file or do similar things in PHP?

Question

I am writing a web frontend for configuring OpenWRT. I'm using PHP to execute commands and all the uci commands are executing without issues. However, OpenVPN configurations cannot be done via UCI and I have to use direct Unix commands on its config file.

These commands run fine in my terminal, but not in PHP:

shell_exec(" cd /etc/openvpn && sed -i '2s/.*/remote 5-nl.cg-dialup.net 443/' openvpn.ovpn && cd'");
shell_exec(" cd /etc/openvpn && sed -i '30s/.*/ca /etc/openvpn/Nethelands/ca.crt/' openvpn.ovpn && cd'");
shell_exec(" cd /etc/openvpn && sed -i '32s/.*/cert /etc/openvpn/Nethelands/client.crt/' openvpn.ovpn && cd'");
shell_exec(" cd /etc/openvpn && sed -i '34s/.*/key /etc/openvpn/Nethelands/client.key/' openvpn.ovpn && cd'");

How can I get the tasks above done in PHP? Do I need to write a shell script, or do I need to change the uhttpd permissions?

I am running php on top of uhttpd web server in Openwrt Chaos calmer. with raspberry pi2

"those commands ... execute fine in terminal but not inside the php" Can you be more precise? Are they executing at all? Are you getting any error messages? Try `shell_exec(" date > /tmp/charith && cd /etc/openvpn && echo 'Kilroy was here' > wall")`. That will tell you whether the commands are running, and as what user, and whether that user has permission to write in `/etc/openvpn`. If that looks good, try `"sed -i '…' openvpn.ovpn > /tmp/charith.log 2>&1`. … … … … … … … … … … P.S.  I'm 99.44% sure that you don't need the `&& cd` at the end. — G-Man Says 'Reinstate Monica', Oct 25 '15 at 21:21
Your `sed` command won't work too. Use `'34s@.*@key /etc/openvpn/Nethelands/client.key@' and alike. P.S. I am 96.2% sure you can replace those four `sed` invocations using `sed -i.bak -e '2s@.*@remote 5-nl.cg-dialup.net 443@' -e '30s@.*@ca /etc/openvpn/Nethelands/ca.crt@' -e '32s@.*@cert /etc/openvpn/Nethelands/client.crt@' -e '34s@.*@key /etc/openvpn/Nethelands/client.key@' openvpn.ovpn`. — Mingye Wang, Oct 25 '15 at 22:05
Ah, `sed BLAH BLAH /etc/openvpn/openvpn.ovpn` actually. You don't even need the initial `cd`. Now it's only a matter of permissions. — Mingye Wang, Oct 25 '15 at 22:14
Thanks all for helping me, My sed commands are wrong and uhttpd doesn't have permissions to edit the files in /etc/openvpn. I fixed it with Arthur2e5 answer. — sameera, Oct 26 '15 at 04:25

score 1 · Accepted Answer · edited Oct 26 '15 at 21:34

Fast and crude guess:

Permission denied. Files in /etc are often not changeable by ordinary users, especially web users like your httpd. Run chmod -R +w /etc/openvpn to open up a hole for that, or do some chown thing.

sed command invalid. In commands number 2-4, multiple slashes appeared. Since s is followed by a slash, slashes are used as operand separator and sed won't work with so many invalid operands. Change your sed thing to this:

<?php /* For Syntax */ // cd avoided.
shell_exec("sed -i.php_sed_bak ".
    "-e '2s@.*@remote 5-nl.cg-dialup.net 443@' ".
    "-e '30s@.*@ca /etc/openvpn/Nethelands/ca.crt@' ".
    "-e '32s@.*@cert /etc/openvpn/Nethelands/client.crt@' ".
    "-e '34s@.*@key /etc/openvpn/Nethelands/client.key@' ".
    "/etc/openvpn/openvpn.ovpn"); ?>

How can I run sed to replace lines in a file or do similar things in PHP?

1 Answers1