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
1answer
179 views

Why doesn't text piped into an echo get outputted?

Why doesn't this command output "1"? echo 1 | echo I imagine it working this way: 1. echo 1 (outputs 1) 2. | echo (takes the 1 as an input, then echos it) Isn't this what should happen?
3
votes
2answers
258 views

How do I echo a lot of content in a bash script?

I would like to do echo "[this thing]" This thing is \documentclass{article} \usepackage{rotating} \usepackage{pdfpages} \usepackage{verbatim} \usepackage{amsmath, amsfonts, amssymb, textcomp, ...
3
votes
3answers
506 views

Split a returned block of text into lines in terminal?

When I give commands like echo $PATH or which program, I often get a very large block of text consisting of may directories. This is fairly useless, if I am for example, looking to see if there is or ...
3
votes
4answers
511 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
171 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 ...
3
votes
2answers
7k views

How can I trim the carriage return from text that is being piped in bash?

I'm using this command to get my last typed command: history | cut -c 8- | tail -n 2 | head -n 1 It works very well in bash, removing the line numbers, but there is one problem I have with it, (er, ...
3
votes
2answers
452 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
2answers
355 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 ...
3
votes
1answer
386 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
581 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
186 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
1answer
999 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
5answers
59 views

How to print out “-E” in bash echo?

I want to execute echo and get an output like: $ export EVAR="-E" $ echo "$EVAR" -E I have stored "-E" in a bash variable, say $EVAR. If I execute echo $EVAR, echo will print out nothing. Perhaps ...
3
votes
1answer
210 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 ...
3
votes
2answers
2k 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
2answers
4k 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 ...
3
votes
3answers
215 views

How do I use a multi-character delimiter for array expansion in bash?

I'm reducing the question to (I believe) the simplest case. Let's say I have a script myscript.sh with the following contents: #!/bin/bash IFS='%20' echo "$*" If I run the command as follows, the ...
3
votes
2answers
725 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
22 views

Why only 4 chars get sent to serial port via command-line

I'm trying to communicate with NodeMCU (CP210x USB/UART) from command-line. However it does not respond to my commands. I have set the correct baudrate via stty 9600 raw. echo ...
3
votes
0answers
308 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
2k 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
5answers
279 views

Combination generator with memory and resource management

I have this bash script, which is generating every single combination of arrays in 5 digit long: #!/usr/bin/env bash for combo in \ ...
2
votes
3answers
1k 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
1k 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
509 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
106 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
2answers
40 views

Run a command stored in a variable to echo into a file

How can I get the stored command to work for the following scenario: CMD='echo "test" >> test.txt' $CMD It will work for other scenarios like: CMD='mkdir test' $CMD
2
votes
2answers
48 views

Command behaving differently when saved in a *.sh file

I was not able to find an answer to this question, so maybe one of you guys can help me out :) I wrote some shell scripts to help me automate things, and they work. However, what doesn't work is ...
2
votes
3answers
1k 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
4answers
143 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 ...
2
votes
1answer
1k 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
694 views

What is the difference between the built in echo command and /bin/echo? [duplicate]

I was playing around with the type and which commands and I discovered something strange. type either returns the path or says that a command is a Bash built in. which either returns the path or ...
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
1answer
38 views

Run executable with variable in Bash

I have the following simple script to run an executable: ./executable.x -input input.dat << i input1 input2 i This works perfectly and all is right with the world. However, I would like to ...
2
votes
1answer
45 views

Debian 8 - problem with no echo in programs

I have a problem, because some programs and functions are not working like in Debian 7. For example: reboot are not sending broadcast message, service [something] [start|stop] not echoing anything, ...
2
votes
1answer
64 views

Check for related file names and delete one of them

I need to write a script that will find files that contain a string in their name. If a file exists that is the same name but without that string, I want to remove the original file. For example, if ...
2
votes
2answers
566 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
491 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
71 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
150 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
78 views

Escape characters from echo -e

I have the following in my .bashrc file I use for a log: function log(){ RED="\e[0;31m" RESET="\e[0m" echo -e "${RED}$(date)" "${RESET}$*" >> "$HOME"/mylog.txt } But when I do ...
1
vote
2answers
38 views

Appending Echo [Password Generator]

I am creating a password generator however I am not get the passwords to append properly. Here is my script i="0" while [ $i -lt 5 ] do echo -n '#' >> passwords.txt && openssl rand ...
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
176 views

How to make the shell execute only external echo, not the builtin one?

I have a C program which uses system() library function. Below is the source code. #include<stdlib.h> int main() { //Some code system("echo Hello World"); //some code return 0; ...
1
vote
3answers
241 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
414 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
664 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
1answer
136 views

Bash - syntax in echo

When using /bin/bash, what is the difference between the following two cases: echo $IFS echo "$IFS" I observe different outputs.
1
vote
2answers
129 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 ...