The echo tag has no wiki summary.
0
votes
1answer
32 views
Using the Echo Command with Sleep command
So I asked a question on here a few weeks ago and the response I got was helpful but I figured I would add some info to get a better response.
I work with a computer system that has 8 servers (4 ...
3
votes
1answer
149 views
Prevent hanging of “echo STRING > fifo” when nothing is reading that FIFO
When I echo something to a named pipe made with mkfifo, it hangs if no process is reading from that pipe. How can I prevent that, i.e., stop that from hanging?
And by the way, why is that hanging ...
78
votes
3answers
7k views
Why is “echo” so much faster than “touch”?
I'm trying to update the timestamp to the current time on all of the xml files in my directory (recursively). I'm using Mac OSX 10.8.5.
On about 300,000 files, the following echo command takes 10 ...
4
votes
4answers
184 views
Bash Scripting : Printing column data in the same row
I have written a bash script to calculate the size of a PostgreSQL database and print the output along with the date when the script was executed in a text file. The script code is as follows:
...
0
votes
1answer
50 views
How to display data in columns in two variables with the same format?
I coded the following to display data formatted in columns:
str1='hello i am robert
and your ma frnd'
str2='thisisaverylongword thisistoohehehe andherefinishthe string
hereis a other ...
7
votes
3answers
195 views
What defines the maximum size for a command single argument?
I was under the impression that the maximum length of a single argument was not the problem here so much as the total size of the overall argument array plus the size of the environment, which is ...
0
votes
3answers
86 views
echo bytes to a file
I'm trying to connect my rasberry Pi to some display using the i2c bus.
To get started I wanted to manually write stuff, bytes in particular to a file.
How do you write specific bytes to a file?
I ...
3
votes
2answers
77 views
Command in variable one are affecting output of other variable when displayed together in UNIX
I am having two file naming Extra_info and Class_info
Class_info contains data :
stuId stuName stuClass
S01 jagdeep First
S02 harsh First
S03 Roop Second
S04 Kali Third
...
6
votes
3answers
187 views
adding an empty first line inside csv file
I input data into a csv by 'echo'-ing some values into another csv.
I tried echo "" and in the next line echo "values" but i get intermittent empty lines..
I need empty line only at the start....
1
vote
3answers
64 views
Print a message from the left-hand side of a pipe
I want to use a variable from the main shell in a sub shell.
I did:
export mysql_root_password="test"
(
echo $mysql_root_password
) | dialog --gauge "Working hard..." 6 50
But it does not ...
3
votes
0answers
116 views
How to create a bash command which creates output that exactly mimics a source text file that can be pasted into bash shell where histexpand is on?
The goal is to create a bash one line command that can be copied and pasted - for instance published on a web forum - and then patches files. See it as a way to distribute a patch file by copy and ...
3
votes
2answers
291 views
print command instead of echo in linux
I simply can print a message in terminal using linux echo command.
prayag@prayag$ echo "prayag works on JVM"
prayag works on JVM
Can I have the same output with print command.
I actually went ...
6
votes
4answers
370 views
What is the difference between echo `date`, echo “`date`”, and echo '`date`'?
What is the difference between these three commands?
echo `date`
echo "`date`"
echo '`date`'
I am confused on what the differences actually are. I think that when the ' are around it means that it ...
2
votes
1answer
215 views
How to echo in shell script without executing the result
I am using this code to print all open files in the specified changelist.
while read line; do
echo "$line"
done < `p4 opened -c $changelist`
However, the line also gets executed and I get ...
1
vote
3answers
56 views
return the numeric value of a indexed variable rather than its name [duplicate]
The following piece of code illustrates my problem
I'm afraid I oversimplified it way too much in the first round.
#!/bin/bash
dogLover=1
catLover=2
for ii in dog cat
do
...
1
vote
3answers
185 views
Is there any alternative to echo daemon to display ip?
Is there any alternative to echo daemon to display ip instead of given string?
For ex:
my ip = 80.1.2.3
server ip = 1.2.3.4
root@my-machine bash$ telnet 1.2.3.4
Trying 1.2.3.4...
Connected to ...
2
votes
1answer
64 views
How to use OSLEC with Alsa as default, not with Pulseaudio or other thirdparty package involved?
Oslec Echo canceller
I have seen some packages used OSLEC and there echo cancle was very well. So for a test simulation, how could i install the OSLEC only with Alsa (i do not use PulseAudio at all, ...
6
votes
7answers
798 views
timestamp before an echo
Exists a nicer way to create timestamp in front of an echo?
Currently I do it this way:
#!/bin/sh
if mount | grep -q /mnt/usb; then
echo `date +%R\ ` "usb device already mounted"
else
...
4
votes
3answers
749 views
Escape sequences with “echo -e” in different shells
I just noticed that it seems like the flag -e does not exist for the echo command in my shell on Linux.
Is this just a messed up setting or is it "normal"?
Some code as an example:
#!/bin/sh
echo -e ...
1
vote
2answers
648 views
Print line numbers of files I am searching through [closed]
I am looking for a way to print the line number of files my script is going through. I have found $LINENO but when I do
echo 'Found foo in file' $(basename $foo) 'on line' $LINENO >> foo.csv
...
5
votes
2answers
262 views
Unix: how to read line's original content from file
I have a data file, the content is as follows:
department: customer service section: A
department: marketing section: A
department: finance section: A
When I read each line, I ...
1
vote
2answers
136 views
Why the inconsistency with using cat vs. echo piped to this sed command?
Inspired by this question: sed: N command does not read single line I wanted to understand why there appears to be an inconsistency between the following 2 commands:
#1. echo
This command produces ...
3
votes
4answers
125 views
How can I print “-n” with `echo`?
I feel really stupid, yet I can't figure how to print the string "-n" with the over 30 years-old command echo.
I tried these:
Michaels:Scripts$ echo -n
Michaels:Scripts$ echo "-n"
Michaels:Scripts$ ...
3
votes
2answers
140 views
insert text in a file using echo command [duplicate]
I am trying to insert some text in a file in the following way
sudo echo "abc-abc/abc/abc" >> /etc/portage/make.conf
but it give me the error
Permission denied
although I am using sudo ...
4
votes
1answer
176 views
Ubuntu unattended install : echo keypress to dialog
Ubuntu 12.04 LTS Server 64
My unattended-mode bootstrap.sh script contains:
apt-get upgrade -y
I know that during execution a primitive UI for GRUB installation will be shown which requires ...
1
vote
1answer
154 views
Cannot echo colored text when inserting in status bar in dwm
I'm using Fedora 18. I'm trying to create a custom status bar in dwm. Now what I'm thinking of is to check if the battery is under a certain level, the background of the battery region in the status ...
2
votes
1answer
69 views
'echo' eats part of the message
I want to write a script that will dump all partitions of my android device through the android debug bridge and since this is a time intensive process I want to notify the user about the progress by ...
0
votes
1answer
361 views
using bash script to output new script: need mixture of variables to be replaced and not replaced
I'm having a problem with bash variable substitution. Here's a silly example of what I am trying to do. I need to output a new script from a bash script. A line (see echo in my example) has a mixture ...
4
votes
2answers
279 views
Quoted vs unquoted string expansion
for i in $(xrandr); do echo "$i" ; done
for i in "$(xrandr)"; do echo "$i"; done
for i in "$(xrandr)"; do echo $i; done
I understand why 1 differs from 2. But why does 3 give a different output ...
0
votes
4answers
293 views
echo a loop with variables command
I have several lists and want to run some commands over them. As lists are long I want to run those commands parallel to each other, hence using nohup.
For every item I tried to echo a loop that ...
-1
votes
1answer
58 views
How to get all Users and echo if they work or not?
How do I get a list of users(given from the command line) with grep and output if they are logged/work or not ?
1
vote
2answers
147 views
How to make sure the shell builtin echo is invoked so that its not visible in process list?
Is this going to be visible in the process listing if the below line is executed from a command line or a shell script
bash -c "echo $password"
or
i just need to do echo $password from within ...
0
votes
2answers
93 views
Supress expansion of * in echo
I am working on a script which dynamically executes some queries on daily basis. These queries are coming from a table in the database.
Here is the sample output of the query table:
...
0
votes
1answer
77 views
the use for echo without argument in shell scripting
I have a following bash script I encountered on the web that prints the power set of a given lines of elements.
p() { [ $# -eq 0 ] && echo || (shift; p "$@") |
while read r ; do echo ...
1
vote
1answer
1k views
How to put value of echo pipe netcat commands into variable [duplicate]
I have this command succession:
echo -ne "/dev/shm/test.sh" | netcat 89.196.167.2 4567
and let's say it return a string like, for example "Hello...bla".
(on the 89.196.167.2 i have made a server ...
3
votes
2answers
233 views
echo string >> file does not work
I wrote the following script:
for filename in `find . -name '*'.cpp | grep $IN_REGEX | grep -v $OUT_REGEX`
do
echo "Output file is $OUTPUT_FILE"
count=`git log --pretty=format: --name-only ...
112
votes
5answers
33k views
Why is printf better than echo?
I have heard that printf is better than echo and I can recall only one instance from my experience where I had to use printf because echo didn't work for feeding some text into some program on RHEL ...
2
votes
3answers
423 views
How to stop `grep` from truncating pipe output
Is there any way to have an echo at the end of a pipe simply append to the current output rather than removing it all? For example, how can I keep the output for my cat and grep and add "END OF ...
-4
votes
2answers
823 views
Redirecting the content of a file to the command “echo”
I have a file named my_file.txt whose content is just the string Hello. How could I redirect its content to the command echo?
I know I have the commands less, cat, more... but I need to do it with ...
4
votes
3answers
10k views
How do I set an environment variable on the command line and have it appear in commands?
If I run
export TEST=foo
echo $TEST
It outputs foo.
If I run
TEST=foo echo $TEST
It does not. How can I get this functionality without using export or a script?
2
votes
1answer
191 views
My echo command doesn't accept switches (echo -n or echo -e)
I have an echo statement in my script as below:
echo -ne "Check Script";
I was expecting it to print
Check Script
but I am getting the below output
-ne Check Script
But when I run the same ...
3
votes
1answer
383 views
Printing colored text using script
When I type below command in the shell I get the OUTPUT in green color.
Command
echo "\033[32mCONNECTING TO abpwrk\033[m";
Output(in green color)
CONNECTING TO abpwrk
But if I use the same ...
4
votes
2answers
279 views
Why am I observing different behaviour of echo?
I am a bash beginner and observed the below behavior of echo
#!/bin/bash
x=" hello"
echo $x
echo "$x"
Now when I run the above code I get
ronnie@ronnie:~$ bash test.sh
hello
hello
...
7
votes
1answer
528 views
Append same text to many files using cat or echo?
How can I write the same content to many text files by using cat or echo in only one command?
For example I want to write "hello" to file1 and file2. I tried:
echo "hello" >> file1 file2
...
5
votes
3answers
477 views
Construct a command by putting a string into a tty
I managed to do this
echo -n "command" > /dev/tty1
The letters appear, and the cursor moves, but they are "ghosts" - if you hit enter, nothing happens (they are not in stdin).
Edit:
In the ...
22
votes
1answer
885 views
Why does echo >file use more real time than echo | sed >file?
The example, below, surprised me. It seems to be counter intuitive... aside from the fact that there is a whisker more user time for the echo | sed combo.
Why is echo using so much sys time when it ...
7
votes
2answers
1k views
Using sed to color the output from a command on solaris
I have a ksh script that must work on both linux and solaris. I'm trying to color the output of specific commands. It works on linux (specifically RHEL6), but not on solaris (SunOS 5.10).
Command ...
6
votes
4answers
9k views
printing colored text using echo
I know that for printing a colored text using echo, for example red color, the code is: echo -e "\e[1;31m This is red text \e[0m"
and I know that in this example, 31 is code of red color and the ...
6
votes
2answers
3k views
Unexpected results testing serial loopback using echo and cat
So I have a standard RS232 serial port that is looped back to itself by simply running a wire from Tx to Rx. I'm testing loopback by running echo and cat in two separate terminals:
cat /dev/ttyS1
...
6
votes
1answer
315 views
differences between echo“”> and > command
I am new to Linux. There is something that is unclear to me.
What is the difference between echo "" > logfile and > logfile ?
When I run the first one, the logfile size doesn't become zero ...
