You might also want to consider using:
instead of:
Note that the two echo commands each open and close the device and each prints a <newline> character that might neither be needed nor desirable from the second echo.
Alternatively, you might want to consider opening the device once at the start of your script using exec to open (and hold open) your device:
(replacing standard input for the entire script in this case, but a different file descriptor can also be specified if some other file is being fed into your script). Then you could consider using the stty utility to set appropriate parameters for your device such as icrnl or -icrnl and igncr or -igncr (depending on whether your device sends <carriage-return> and/or <newline> characters as line terminators when you read data from your device) and ocrnl or -ocrnl, onlcr or -onlcr, and onocr or -onocr depending on what it wants to see as line terminators in commands it receives from your script. (And, of course, check the stty man page on your system for other operands that might simplify using your device.)
I thought about proposing using the stty utility as well but wasn't sure if it would work/apply, as we are dealing with a USB GPIO device.
Using stty might or might not work, but it is really easy to find out...
If the command stty < /dev/ttyACM0 works (printing the current settings for the device), it will work. If it exits with a non-zero exit status and prints a diagnostic similar to:
then it won't work.
Thanks Don. I will try your suggestions today. One question: If I use
to open the port for the duration of the script, what is the command for closing it when I exit the script?
Hello,
I'm works on Ubuntu server
My goal : I would like to read file line per line, but i want to started at the end of file.
Currently, I use instructions :
while read line;
do
COMMAND
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Heyas
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Hi All,
Am trying to write wrapper shell/bash script on a utility tool for which i need to pass 2 files as arugment to execute utility tool.
Wraper script am trying is to do with above metion 2 files.
utility tool accepts :
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#!/bin/bash
while read line
do
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done<file
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device for check3: /dev/ttyr002
device for check4: /dev/ttyr002
I changed the tty setting for check3 in:
/etc/printcap
/var/spool/lp/admins/lp/printers/check3
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I am using the while-loop to read a file.
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I have problem with C programming. I want to send & receive data through serial communication. I send data(command) to device to get data from device but when receive data, it can't get altogether of data.
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Hello!
I am working on an application which reads environmental instruments which have serial ports. The application requires a serial port to be present to talk to the device (i.e. /dev/ttyS0 ). In some instances the environmental devices will be 100's of yards away from the computer, so a... (5 Replies)
Hey!
I'm trying to figure out a sollution for a problem I have at my company with an Iomega MiniMax 500 GB USB disk.
If i run cat /proc/bus/usb/devices
I get this information:
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D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00... (2 Replies)
hi. Im trying to install a switch.
And the manual says i should type a command including a SerialPortDevicePath. which is the filepath to serial port used for connection.
However.. nothing about how to find this info.
Could anyone help me where to find this path?
thx
mr.T (6 Replies)