Questions about either the shell builtin or `/bin/echo`. This tag should not be used if your question is simply about printing to the terminal, only apply it if your question is specific to the `echo` command.

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3
votes
2answers
373 views

How do I echo an expression with both single and double quotes?

I have tried many things, but I'm new to the shell. Is it possible to have both double and single quotes within an echo? I want to generate echo "scan 'LPV',{FILTER => "(PrefixFilter ...
3
votes
1answer
363 views

Shell script doesn't paint last line of stdout to screen without user input

I have a shell script that's happily doing all my backup process and writing progress to stderr and stdout, with one exception — the last line doesn't get written to my terminal (if I call the script ...
3
votes
2answers
444 views

Bash - echo line by line, ignoring the space between the lines

I had read the post on: bash - replace space with new line, but it does not helped to solve my issue. [My Directory] [root@testlabs Config]# ls Archive Backup_Files config_file.tgz ...
3
votes
3answers
148 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 There is no output. ...
3
votes
2answers
823 views

What is the format for piping a message into sendmail?

I am using the following command to create messages on the fly, and send them: echo "Subject:Hello \n\n I would like to buy a hamburger\n" | sendmail email@example.com It seems that when you send ...
3
votes
1answer
707 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 ...
3
votes
2answers
1k 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 ...
3
votes
1answer
94 views

echo result from subshell in zsh

In zsh, the following 2 commands results differently: a=$(</etc/hosts) && echo $a echo $(</etc/hosts) The 1st prints contents line by line, while the 2nd prints contents as a whole in ...
3
votes
2answers
588 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 ...
3
votes
0answers
262 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 ...
2
votes
5answers
393 views

How to add new lines when using echo

Why the following command does not inserts new lines in the generated file and what's the solution? $echo "Line 1\r\nLine2" >> readme.txt $ cat readme.txt Line 1\r\nLine2
2
votes
3answers
5k 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 ...
2
votes
3answers
980 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 ...
2
votes
5answers
504 views

How to overwrite stdout using echo? [closed]

We know to overwrite bar.txt, we can use this: echo "foo" > bar.txt but how can we overwrite to the standard output? I tried this command: echo "foo" > but it failed. I want this because ...
2
votes
1answer
450 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 ...
2
votes
1answer
95 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 ...
2
votes
3answers
32 views

echo and command substitution

I wrote a very basic script of command substitution which is below: #!/bin/bash files=$(ls *.fastq); echo $files The directory contains bunch of .fastq file and I just want to use echo command to ...
2
votes
1answer
151 views

Avoid backslash expansion with echo in dash

First create a file with this exact content: a\nb I named this file foo, if I run the following, it prints the exact content of the file: bash -c 'bar=$(cat foo);echo "$bar"' But if you run it ...
2
votes
1answer
914 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 ...
2
votes
1answer
5k 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 ...
2
votes
2answers
333 views

How do I expect 'echo -e “? \c”'?

I'm an absolute newbie to the UNIX world and have been asked to write a script that interacts with another one - but I'm stuck. The script that I interact with echos the following and I need to send a ...
2
votes
2answers
326 views

Read Multiple Entries from an Input File

I wrote a program in Fortran that asks me for latitude and longitude and the name of the output file every time I run it. It works great. What I have been meaning to do is run this program for the ...
2
votes
0answers
63 views

Is there a difference between double quoting a variable or a whole line in echo

When you type, for example, echo Variable "$var" is not initialised. and echo "Variable $var is not initialised." the front end result is the exact same (as far as I know, at least). But I was ...
2
votes
1answer
132 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, ...
1
vote
2answers
2k views

Alias Loop in csh

Why is there an Alias loop error created here: alias df 'printf "\n"; df -hP | column -t' But not here: alias df 'df -hP | column -t' I realize I could call the alias something else and still ...
1
vote
3answers
179 views

How to print new lines at the end of functions?

If I type echo hello, my terminal looks like this: My-Computer:~ user$ echo hello hello My-Computer:~ user$ But if I have a function like this stringen () { cat /dev/urandom | env LC_CTYPE=C tr ...
1
vote
2answers
1k views

How can I right-justify variable length output?

So I don't want this: echo "9" 9 Rather I need this, with e.g.: 4 spaces before it: MAGICK "9" 9 So if I try it with 10: MAGICK "10" 10 then it will just have 3 spaces before it. How ...
1
vote
3answers
383 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 ...
1
vote
2answers
517 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 ...
1
vote
2answers
272 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 ...
1
vote
2answers
68 views

echo with backspace

I am trying to figure out why this happens in bash. Ok this is easy enough. $ echo -e 'a\txy\bc' a xc Ok this is easy enough. $ echo -e 'a\txy\b\b\b\b\b\b\b\b\bc' ac xy Ok this is easy ...
1
vote
2answers
41 views

change colour of `echo` for particular line in shell script in Linux?

i want to change colour of echo particular statement in Linux shell script example : echo "invalid entries" echo "valid entries" echo "valid entry" i want red color for echo "invalid ...
1
vote
4answers
84 views

echo \\* - bash backslash escape behavior, is it evaluated backwards?

So in bash, When I do echo \* * This seems right, as * is escaped and taken literally. But I can't understand that, when I do echo \\* \* I thought the first backslash escaped the second one ...
1
vote
1answer
141 views

how to `echo` 'formatted' man page of some command to text file [duplicate]

When I execute echo `man ls` > tem.txt I get unformatted output in the text file, I mean output without any new lines, just continues sentences. How do I get formatted output ? For example, ...
1
vote
2answers
50 views

Background processes mix up order of shell script execution

Can someone explain me why the script echo one && echo two & echo three && echo four gives me [1] 3692 three four one two [1]+ Done echo one && ...
1
vote
2answers
66 views

Bash script strange behavior with echo - printf in a file

I want to print part of the content of a .csv file in another file if there is a match with some condition: The csv content is like this abc test;ABCtest.it xyz test;XYZtest.com I read the content ...
1
vote
1answer
49 views

How to configure the system in order beeing able to hear the sound of the \a escape character?

I read, that if I execute: echo -e "\a" a sound emerges, but frankly speaking, i executed this command several times and no sound happened.
1
vote
2answers
3k 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 ...
1
vote
1answer
65 views

Sending serial commands with echo vs screen session

I have a small LED matrix controlled by a display driver that accepts serial commands to update the display. I'm successfully controlling it via node with the node serial package, however I'd like to ...
1
vote
1answer
60 views

How to echo makefile variable through Make's $(shell …)

I have a GNU makefile. The makefile has a few tests (around line 65 from the linked file): UNAME = uname MACHINE ?= $(shell $(UNAME) -m) SYSTEM ?= $(shell $(UNAME) -s) IS_X86 = $(shell echo ...
1
vote
1answer
60 views

echo a colored text with tabs

I have the line below to echo values with tab between them. The text is also colored, however, some\t does not work. The output of this one below will have the first two \t not working. echo ...
1
vote
1answer
96 views

Echo newline with quotes [duplicate]

For: $hello="hello > world" Why does echo not print the newline for: echo -e $hello But if I put $hello in quotes it does. $ echo "$hello" hello world Is this because of ANSI-C Quoting? ...
1
vote
1answer
154 views

./a.out && echo $? only prints return value if return = 0

echo $? in the following scenario does not display the return value, i.e. 1. echo "int main() { return 1; }" > foo.c gcc foo.c && ./a.out && echo $? However, echo $? works when ...
1
vote
3answers
69 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
1answer
350 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 ...
1
vote
1answer
42 views

Not getting the desired output for echo command [duplicate]

Below is my script. #!/bin/bash SERVERS="sl20rht00-t" #SERVERS="shcbrht01-t" USR="adm-dt-c" for host in $SERVERS do ssh -tt $USR@$host 'sudo cp /etc/sudoers /Backups/sudoers_11thmarch2015; sudo cp ...
1
vote
2answers
34 views

How would I loop this command?

A snippet of my code is shown below. The script currently closes if its not able to find the path. [echo "could not find $REPLY, ensure the path is correct and try again"] Instead I would like it ...
0
votes
4answers
1k 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 ...
0
votes
2answers
118 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
34 views

bash: cut command produces nothing (just a blank line)

I have a problem with being able to echo a part of a string Here is a simplified version: t=no_1187985:/home/my.name/testing/no I want to echo no_1187985 only so: tt=$(echo $t | cut -d":" -f 1) ...