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Showing posts from 2018

"No child processes" error on Linux

A problem was reported by a customer. They were getting a failure and in the logs it reported error → waitpid failed 'Reason: No child processes' The “No child processes” error came from waitpid() after using  fork/spawn to launch a utility to load data into a data base. Upon detailed investigation it appears it is possible that some other process that the user is running has changed the default handler for SIGCHLD - possibly the shell (e.g. bash!) used to launch our server processes. If the signal handler is set to SIG_IGN then when a process is started using fork()/exec() the return code from the process is NOT returned and waitpid() cannot retrieve the response code. The most likely reason for "No child processes" error from waitpid() is that the signal handler for child processes (SIGCHLD) is not set to SIG_DFL. This should not be possible however it seems that on Linux a process run in the shell (or maybe a shell process) can set it

"Tap and go" using "Card" or "Phone"?

I set up Android pay on my phone and tried it a few times. I have found I get out my card and use tap and go instead. It is all about convenience. I find it is just as easy to get the card from my wallet, remove it from the protective sleeve as it is to get my phone and unlock the screen. I think it is also a politeness thing. I always try not to be engrossed in my phone when I am going through the check outs. I keep my phone in my pocket so as to be courteous and pay attention to my shopping. Then there is habit. I am used to getting my wallet out to pay. Perhaps if it was quicker to unlock my phone I might get into the habit of using it to pay.

Charging your devices when travelling

One of the challenges when traveling is being able to connect and charge all the different devices we take with us. These devices differ depending on the purpose of the trip (business or pleasure) but have the same challenges.When traveling for pleasure you may be staying with friends or at an AirBnB. What is available may be unknown. Many hotels cater for international travelers and have sockets that allow many different plugs to be used - The JW Marriott in Bangalore allows you to plug in any type of plug (all that I have seen!). One hotel in Sydney had USB charger ports available. The first challenge is being able to plug your charger in. When traveling for work I always carry two adapters that convert from the local plug standard to the plugs required for my devices and chargers. An alternative is to carry one adapter and a power board. The exception to the two adapters is when I am traveling to multiple countries which have different plugs! In those cases a universal adapter is

When a picture isn't enougth!

I bought a Bluetooth speaker online a few years ago and when it arrived it was much smaller than I expected. The picture made it look bigger and I failed to check the dimensions. I bought a sub-woofer before that and it was the size I expected. Then I bought another sub-woofer a week ago, expecting it to be a similar size. The price was about the same. The speaker came in a large box and is the size of a small fridge, at least 3 times the size I expected! The moral of the story? Pay attention to the dimensions!