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
37 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 ...
1
vote
2answers
42 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
32 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
42 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 ...
0
votes
0answers
40 views

echo `“hello terminal” > /dev/terminal` - works for /dev/tty[2-5] but not for /dev/pts/n

I'm trying to get to know the input output systems of unix/linux systems better. Since terminals and devices are implemented to interface as ordinary files, I assumed I could on any desired terminal ...
0
votes
1answer
30 views

Glob pattern argument for echo command

echo *.c in bash, treats the argument as a constant and prints *.c. How to force it to consider it as a glob pattern and print the list of files/folders ending with .c?
1
vote
1answer
37 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.
5
votes
3answers
303 views

How to put a newline special character into a file using the echo command and redirection operator?

I would like to create a file by using the echo command and the redirection operator, the file should be made of a few lines. I tried to include a newline by "\n" inside the string: echo "first ...
5
votes
1answer
117 views

using ! character in echo

I am messing with echo and having issues with echo displaying the ! character. I tried this. echo -e "Wake!\nUp! bash: !\n!: event not found Then this # echo "Wake\!\nUp!" Wake\! Up! Well now ...
0
votes
1answer
42 views

Using echo to alter a files md5

I need to alter the md5 for some of my files, I was told to run the following echo >> /path/to/file.iso I was just wondering, What does actually do to the file. It seems to work and change ...
1
vote
1answer
36 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
4answers
47 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 ...
0
votes
1answer
41 views

Why does the input to xargs is 1 string but without is strings in separate line?

I am trying to pipe file to rm via xargs. I understand that what I am tryng to do could be done by git clean but I am practicing the cli. I tried this: for files in $(git status --porcelain| sed ...
-1
votes
1answer
36 views

sudo issue during echo something to a root file [duplicate]

I have a problem, during write something into a root file: $ ll /sys/bus/usb/devices/3-2/power/wakeup -rw-r--r-- 1 root root 4096 Feb 16 17:28 /sys/bus/usb/devices/3-2/power/wakeup $ sudo echo ...
0
votes
0answers
32 views

How do I add a \n to the end of the record on file using AWK

I have a file that can contain 1 or many lines oracle1.txt oracle2.txt oracle3.txt How do I using AWK put a \n after the last line only so it will show oracle1.txt oracle2.txt oracle3.txt\n I ...
0
votes
3answers
395 views

create XML file using bash script

I want create simple xml file using bash script ( not with dom ) but when I set value in the line then echo print the $lorem word and not the val lorem=LOL echo '<root><foo ...
2
votes
0answers
60 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
106 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 ...
1
vote
1answer
66 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? ...
5
votes
1answer
174 views

echo colored text which changes colors dynamically

Is there any way that i can print a colored text on console which keeps on changing its colors dynamically(with or without a specified time interval) just like some greeting cards in which the ...
1
vote
1answer
73 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
32 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 ...
1
vote
2answers
158 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 ...
1
vote
3answers
158 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 ...
6
votes
4answers
516 views

Back to back Pipes into a Command

Is there a way to pipe back to back values into a command? e.g. If I can command.pl and want to pipe in response, then y to confirm (because it doesn't have a way to auto confirm)? I've tried echo ...
7
votes
3answers
491 views

in Bash, how to not include extra arguments in an alias?

I am trying to do something like alias ftp='echo do not use ftp. Use sftp instead.' just so that ftp will not be accidentally used. But I noticed that ftp abcd.com will cause the command to ...
3
votes
2answers
317 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 ...
6
votes
3answers
510 views

How do I print '-e' with echo?

I know that echo -e is not an ordinary command. I have tried echo '-e' and echo \-e but they still don`t work.
3
votes
2answers
315 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 ...
0
votes
2answers
51 views

zsh function output removes leading whitespace

Consider the following two commands and their outcome: 14:57 : echo $(echo " ABC") ABC 14:57 : echo " ABC" ABC Version of zsh: zsh 5.0.5 (x86_64-apple-darwin14.0) Why does the first one ...
4
votes
3answers
1k views

Add text with echo but start with new line if file not empty

I'm trying to create next script echo "#!/bin/sh" >/script echo "del x.txt" >>/script witch is ok if /script file is empty, if not - will append first line to last text #!/bin/sh del ...
14
votes
4answers
2k views

What does echo $-1 display?

What does the output of echo $-1, echo $-2, echo $-3.. mean? On one of my Linux boxes, it shows me: echo $-1 imsBEl1 echo $-2 imsBEl2 And on another Linux box, it shows: echo $-1 himBH1 echo $-2 ...
5
votes
3answers
764 views

Why does “$ sudo echo 'yo' ” work even though echo is a shell built in function? [duplicate]

I understand that sudo cd /directory will return: sudo: cd: command not found because cd is a shell builtin and not a binary. But then, why does sudo echo 'this is a test' works fine? What ...
0
votes
0answers
329 views

BC returns syntax error

#!/bin/bash cd ~/simplesim-3.0/benchmarks INSTS=$(grep "sim_num_insn" ./anagram.txt | awk '{print $2}'); IL1_ACCESSES=$(grep "il1.accesses" ./anagram.txt | awk '{print $2}'); IL1_MISSRATE=$(grep ...
0
votes
1answer
121 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 ...
3
votes
2answers
211 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, ...
1
vote
1answer
115 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 ...
12
votes
6answers
1k views

What is the reverse of echo -e?

If I have a string with nonprintable characters, new lines, or tabs, is there a way I can use echo to print this string and show codes for these characters (e.g., \n for new line, \b for backspace)?
4
votes
3answers
203 views

How do I capture stdin to a variable without stripping any trailing newlines?

In a shell script... How do I capture stdin to a variable without stripping any trailing newlines? Right now I have tried: var=`cat` var=`tee` var=$(tee) In all cases $var will not have the ...
5
votes
2answers
254 views

echo of a string with an exclamation point

Here are what I put in bash and the results I got about 'echo': $ echo '!$' !$ $ echo "!$" echo "'!$'" '!$' I'd like to know how 'echo' deals with the second input. It seems to me that ...
15
votes
3answers
1k views

why 'echo --help' doesn't give me help page of echo?

I tried 'man echo' in Bash and it told me that 'echo --help' will display help then exit, and similarly, that 'echo --version' will output version and exit. But why it doesn't work ? 'echo --help' ...
9
votes
3answers
654 views

Why does “wc -c” print a value of one more with echo?

When running echo abcd | wc -c it returns 5. But the word abcd is only 4 characters long. Is echo printing some special character after the word abcd? And can I prevent echo from printing that? ...
1
vote
5answers
230 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
2answers
228 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 ...
3
votes
2answers
285 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
3answers
312 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
1answer
524 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 ...
92
votes
3answers
9k 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 ...
5
votes
4answers
777 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
610 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 ...