- How to preserve exif metadata in images in Linux
1.0 Exif metadata not preserved by image editing program
Problem: After an image is developed and edited by image editing software and saved in a format like JPEG, it does not have the Exif metadata.
Surprisingly, quite a few image editing programs do not preserve the Exif metadata of images and attempts ...
- How to add the IPTC metadata in photographs using exiv2 in Linux
1.0 Adding the IPTC metadata
After a photograph has been taken and processed, it might be necessary to add IPTC metadata before it can be published. If your image editing software does not support adding of IPTC metadata to the image, you can accomplish this is by using the exiv2 command ...
- How to get the value of Pi in bc calculations
While using bc for calculations, the value of π is sometimes required. Sure, you might remember it as 3.1416, but it is better to use a higher precision value. And it's quite simple to do that.
First, we need to start bc with the option
- Error while executing the dig command
While executing the dig command, the
sendmsg() failed: Operation not permittederror was printed.
$ dig example.com ../../../../lib/isc/unix/net.c:581: sendmsg() failed: Operation not permitted ../../../../lib/isc/unix/net.c:581: sendmsg() failed: Operation not permitted ...
The error was resolved after adding the following iptables rules.
iptables -I OUTPUT 1 -p udp -s ...
- Analyzing the NGINX web server log file
Given an nginx web server log file, we might like to know who are the visitors to our website. One can go line by line through the log file, but that is tedious. It would be nice if we can get one line per client visiting the website, giving the IP ...
- Android adb install failure INSTALL_PARSE_FAILED_NO_CERTIFICATES
A signed APK of an Android app was built using the Android Studio. When we tried to download the signed APK to a device using the adb command, the command failed with the error, INSTALL_PARSE_FAILED_NO_CERTIFICATES.
$ adb install app-release.apk app-release.apk: ...
- nginx drupal sitemap 404 not found
While trying to open sitemap.xml of a site served by nginx and built using Drupal CMS, the
404 Not Founderror was received. The nginx log file, error.log gave the error as,
80 open() sitemap.xml failed (2: No such file or directory).
- optipng: Error: Can’t back up the existing output file
While running optipng on a png file, the following error was obtained,
Error: Can't back up the existing output file
The file was not having the write permission. Once, the write mode bit for the file was set, optipng worked fine.
$ ls -ls ...
- Getting a project from GitHub
While searching on a topic, you land up on a GitHub page with code. The code looks interesting. But you can not work on it on GitHub. You need to get it on your computer to work on it. How to get it on your computer?
2.0 Solution: Get the repository
The code displayed on the ...
- Failed to send 300 byte long packet over fallback interface
While configuring a server, the following errors were noted in the logfiles.
send_packet: Operation not permitted dhclient.c:2386: Failed to send 300 byte long packet over fallback interface. DHCPREQUEST on eth0 port 67 (xid=0x1580bfd0) ...
There are two possibilities depending upon whether DHCP is being used for getting the network IP address or not.
- Dovecot: imap Error: open (/var/mail/username) failed
While configuring mail on a Ubuntu Linux server running the Postfix mail server and Dovecot IMAP server, the following errors were observed in the mail log files,
dovecot: imap(user1): Error: open(/var/mail/user1) failed: Permission denied (euid=1002(user1) egid=1002(user1) missing +w perm: /var/mail, we're not in ...
- Not able to access files on Android device in Nautilus from Linux desktop
After connecting an Android based phone with a Linux desktop using the USB cable, the files on the device are not shown by the Nautilus file manager. After clicking the tab for the device, an empty screen is displayed.
Recaptcha: Error for site owner
The login form for a Drupal based site had the username, password and recaptcha fields. However, instead of showing the image and input box, recaptcha displayed
ERROR for site owner, Invalid domain for site key. Thus, it became impossible to login to the site. This effectively locked access to the administration ...
- Android: AdbCommandRejectedException getting properties for device
From Android Studio, the connection to the device for debugging was not getting established. The ADB logs gave the repeated error,
PropertyFetcher: AdbCommandRejectedException getting properties for device ????????????: insufficient permissions for device
- As described in the documentation, Using Hardware Devices, a file /etc/udev/rules.d/51-android.rules was created.
- Using the
- Error while loading shared libraries: libz.so.1
While building an Android app project under Studio, the build process terminated with the error,
/home/user1/Android/Sdk/build-tools/22.0.1/zipalign: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory Error:Execution failed for task ':app:zipalignDebug'. > Process 'command '/home/user1/Android/Sdk/build-tools/22.0.1/zipalign'' finished with non-zero exit value 127
The problem was resolved by installing the
- Error while executing the dig command