bash - Use sudo to change file in root directory -

-

i'm trying write script configure resolv.conf , /etc/network/interfaces automatically. i'm running commands "sudo", i'm getting "permission denied" errors.

sudo apt-get --assume-yes install vsftpd sudo "nameserver 8.8.8.8" >> /etc/resolv.conf sudo python setinterfaces.py sudo chattr +i /etc/network/interfaces sudo apt-get --assume-yes install lamp-server^

lines 2 , 3 permission denied errors, lines 1 , 5 did run. setinterfaces.py supposed overwrite /etc/network/interfaces'.setinterfaces.pyworks when pointed @ home folder not theinterfaces` file.

any idea? have changing ownership? ideally i'd 1 command script, can call , run. i'm writing script people not experienced in *nix.

the sudo command executes command give under root account. in simplest form, syntax is:

sudo command args...

for example:

sudo whoami

prints root.

if type, did in question:

sudo "nameserver 8.8.8.8" >> /etc/resolv.conf

then it's not going work; try execute command named "nameserver 8.8.8.8", doesn't exist. problem there you're missing echo command.

this:

sudo "echo nameserver 8.8.8.8" >> /etc/resolv.conf

still won't work because there's no command called "echo nameserver 8.8.8.8". entire string passed sudo single argument. needs see command , each of arguments separate argument.

so this:

sudo echo nameserver 8.8.8.8 >> /etc/resolv.conf

is getting closer -- still won't work. executes echo command root -- echo requires no special privileges, there's no point in executing root. >> /etc/resolv.conf redirection executed shell, running you, not root. since don't have permission write /etc/resolv.conf, command fails. sudo command never sees redirection.

you need redirection executed under root account, means need shell process running root. solution is:

sudo sh -c 'echo nameserver 8.8.8.8 >> /etc/resolv.conf'

this launches shell root process. shell executes command line echo nameserver 8.8.8.8 >> /etc/resolv.conf. since have root shell executing both echo , output redirection, should work.

(i suggest grabbing copy of /etc/resolv.conf file before doing this, make sure can recover if accidentally clobber it.)


Comments

Post a Comment

Popular posts from this blog

c++ - OpenCV Error: Assertion failed <scn == 3 ::scn == 4> in unknown function, -

-
i read alot other solution still confused should mine... #include <opencv2/objdetect/objdetect.hpp> #include <opencv2/highgui/highgui.hpp> #include <opencv2/imgproc/imgproc.hpp> #include <iostream> #include <stdio.h> using namespace std; using namespace cv; int main(int argc, const char** argv) { //create cascade classifier object used face detection cascadeclassifier face_cascade; //use haarcascade_frontalface_alt.xml library face_cascade.load("haarcascade_frontalface_alt.xml"); //setup video capture device , link first capture device videocapture capturedevice; capturedevice.open(0); //setup image files used in capture process mat captureframe; mat grayscaleframe; //create window present results namedwindow("outputcapture", 1); //create loop capture , find faces while (true) { //capture new image frame capturedevice >> captureframe; ...
Read more

php - render data via PDO::FETCH_FUNC vs loop -

-
i've been using 2 methods render data. the first one: function name($id,$name){ return '<div id="'.$id.'">'.$name.'</div>'; } echo implode($pdo->query("select id,name user")->fetchall(pdo::fetch_func,'name')); the second one: $users = $pdo->query("select id,name user")->fetchall(pdo::fetch_obj); foreach($users $user){ echo name($user->id,$user->name); } i don't understand how pdo::fetch_func works. tried figure out. however, not well-documented. could please explain fetch mode? , also, 1 performs better? thank you. both methods wrong , have learn how use templates , how separate business logic presentation logic. $users = $pdo->query("select id,name user")->fetchall(pdo::fetch_obj); tpl::assign('users', $users); is code business logic part. then in template <?php foreach $users $row): ?> <div id="<?=$...
Read more

The canvas has been tainted by cross-origin data in chrome only -

-
uncaught securityerror: failed execute 'getimagedata' on 'canvasrenderingcontext2d': canvas has been tainted cross-origin data i getting above error in chrome. code(following) works fine in mozilla. have not corss domain issue. why above error in chrome? var wheel_canvas, wheel_context, can_w, can_h, wheel_grd; var large_radius = 160; var small_radius = 120; var wheel_canvas = document.getelementbyid('wheel_canvas'); var wheel_context = wheel_canvas.getcontext('2d'); var can_w = $(wheel_canvas).width(); var can_h = $(wheel_canvas).height(); var centerx = can_w / 2, centery = can_h / 2; var wheel_grd = null; test('#ff0000'); function test(hex) { $('#clrpicker').css({'left': 210, 'top': 210 }); inverted = hexbw(hex); $('#color_val_show').val(hex); current_color_hex_val_selected = hex; $('#color_val_show').css({'color':inverted,'background':hex}); fillgradient...
Read more