03-29-2020
That was pretty interesting
9 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Heres a script i wrote as a bit of practise. What it does is insert a line in the middle of a file. The line being $1 and the file being $2
#!/bin/bash
rm tempfile
touch tempfile
count=1
linenum= `wc -l < $2`
if
then
echo $1 >> $2
else
even=`expr "$linenum" % 2`
if
then... (3 Replies)
Discussion started by: Quesa
3 Replies
2. Shell Programming and Scripting
if input to the perl program is ' ( p * ((a+b) * (c+d))) + q ' it shuld give the output as ' pac + pad + pbc + pbd + q ' .can anyone suggest a way to do this ? (7 Replies)
Discussion started by: Anuj8584
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3. Shell Programming and Scripting
Hello,
I'm trying to write a while loop for a decimal value in tcsh which I know can't be done. Instead I want my increments to be one order of magnitude too large and then divide it by 10 when I use the variable. However, I don't know how to divide my variable and set it as another.
set... (1 Reply)
Discussion started by: DFr0st
1 Replies
4. Shell Programming and Scripting
Hi All
I've made a few scripts which using GDAL extract the value of a pixel within a given raster. The purpose is to work out the combine value of every pixel. I thought there may have been an easier way to do this but alas!
The code below extracts the pixel value at position X Y. The... (3 Replies)
Discussion started by: StudentFitz
3 Replies
5. Shell Programming and Scripting
Hi, I am trying to make a maths calculator that:
1. Prompts the user for a number.
2. Prompts the user for an operation (add, subtract, divide or multiply)
3. Prompts the user for a number.
4. Prompts the user for another operation (same as above) OR the option to get the result for the... (4 Replies)
Discussion started by: johnthebaptist
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6. Shell Programming and Scripting
Hi,
Need help on this. I need to increment a variable by 1 but retain as 2 characters.
I am using expr to do additions:
NEWSERIAL=`expr $SERIAL + 1`
$SERIAL can range from 01-99. After adding "1", I need the result to be 2 characters, eg: 02+1 = 03. By default expr will truncate the... (4 Replies)
Discussion started by: vchee
4 Replies
7. Shell Programming and Scripting
Hi guys...
I am loving this integer maths thing.
64 bit systems are certainly easier than 32 bit, but hey, I don't intend to leave out my fav' platform.
Using one of the 'Brothers' methods, URL inside the code.
#!/bin/sh
#
# #!/usr/local/bin/dash
# e_constant.sh
# Brother's formula .
#... (2 Replies)
Discussion started by: wisecracker
2 Replies
8. Programming
Here is a rapid prototype app I just put together which might be of interest to some people.
Basically, I have parsed the data from a Chinese web site which is tracking the Wuhan coronavirus, and cache that data every minute via a local cron file and make a simple API available to a Blink app. ... (6 Replies)
Discussion started by: Neo
6 Replies
9. Programming
With a little bit of work, was able to build a nice "Wuhan Coronavirus Status" app using MQTT and the IoT-OnOff app. More on this technique here:
ESP32 (ESP-WROOM-32) as an MQTT Client Subscribed to Linux Server Load Average Messages
The result turned out nice, I think. I like the look and... (10 Replies)
Discussion started by: Neo
10 Replies
WATCH(1) Linux User's Manual WATCH(1)
NAME
watch - execute a program periodically, showing output fullscreen
SYNOPSIS
watch [-dhv] [-n <seconds>] [--differences[=cumulative]] [--help] [--interval=<seconds>] [--version] <command>
DESCRIPTION
watch runs command repeatedly, displaying its output (the first screenfull). This allows you to watch the program output change over time.
By default, the program is run every 2 seconds; use -n or --interval to specify a different interval.
The -d or --differences flag will highlight the differences between successive updates. The --cumulative option makes highlighting
"sticky", presenting a running display of all positions that have ever changed.
watch will run until interrupted.
NOTE
Note that command is given to "sh -c" which means that you may need to use extra quoting to get the desired effect.
Note that POSIX option processing is used (i.e., option processing stops at the first non-option argument). This means that flags after
command don't get interpreted by watch itself.
EXAMPLES
To watch for mail, you might do
watch -n 60 from
To watch the contents of a directory change, you could use
watch -d ls -l
If you're only interested in files owned by user joe, you might use
watch -d 'ls -l | fgrep joe'
To see the effects of quoting, try these out
watch echo $$
watch echo '$$'
watch echo "'"'$$'"'"
You can watch for your administrator to install the latest kernel with
watch uname -r
(Just kidding.)
BUGS
Upon terminal resize, the screen will not be correctly repainted until the next scheduled update. All --differences highlighting is lost
on that update as well.
Non-printing characters are stripped from program output. Use "cat -v" as part of the command pipeline if you want to see them.
AUTHORS
The original watch was written by Tony Rems <rembo@unisoft.com> in 1991, with mods and corrections by Francois Pinard. It was reworked and
new features added by Mike Coleman <mkc@acm.org> in 1999.
1999 Apr 3 WATCH(1)