All Questions
26
questions
0
votes
2
answers
190
views
Why is echo "\*" the same as echo "\\*"
Title.
echo "\*" has the exact same output as echo "\\*", \*. I am using GNU bash 5.2.15.
I expected echo "\\*" to output \*, but I do not know why echo "\*" ...
4
votes
2
answers
653
views
How to print a double quote in POSIX scripting?
So far, I've been using "\"" to print a double quote:
$ x="abc def"
$ echo "x=\"$x\""
x="abc def"
However, it seems like that behavior is ...
0
votes
1
answer
30
views
how to arrange quotes in this bash command
my_cmd --attr1 $(($1-$2)) --attr2 $(($1-$2+$3)) --attr3 $(($2+1))
I have this command and I would like to debug it (put it in echo and see how command will look like) but I am struggling with ...
3
votes
1
answer
3k
views
Shell command executed differently in a terminal and script
The following sequence of commands
ch=`echo "b_d" | sed 's/_/\\\\\\\\_/'`
echo $ch
when executed in a terminal or via source give an output
b\\_d
When ran as a scipt
sh script.sh
where the ...
14
votes
2
answers
12k
views
Is it dangerous to run echo without quotes?
I've seen couple of similar topics, but they are referring to not quoting variables, which I know could lead to unwanted results.
I saw this code and was wondering would if it be possible to inject ...
2
votes
2
answers
1k
views
Why does the command echo `echo \\\z` output \z?
The command echo $(echo \\\z) is from the book
, I don’t understand why it outputs
\z
I think it should output
z
1
vote
2
answers
3k
views
Why echo command does not need "-e" option when escaping "$" character with a backslash
This is regarding bash builtin echo. Per Bash documentation the -e option enables interpretation of backslash escapes.
If I execute echo "Total Amount \$500", I see the expected output Total ...
5
votes
3
answers
17k
views
Echo new line and string beginning \t
Sure, echo -e can be used so that \n is understood as a new line. The problem is when I want to echo something beginning with \t e.g. "\test".
So let's say I want to perform echo -e "test\n\\test". I ...
7
votes
2
answers
887
views
Why does dash's echo expand \\\\ differently to bash's echo?
I have a little open source project that for various reasons I've tried to write in reasonably portable shell script. Its automated integration tests check that hostile characters in path expressions ...
13
votes
2
answers
3k
views
What is the difference between single quoted $'string' and double quoted $"string" in bash?
I was trying to execute new line using echo and tried following two commands:
First command:
echo $'Hello World\nThis is a new line'
Response:
Hello World
This is a new line
Second command:
echo ...
0
votes
2
answers
168
views
trying to escape quotes
I have tried numerous ways to print this line in a script:
alias myname='export PATH="/path/to/bin:$PATH"'
All of them have different problems.
The last I tried (and remember!) is:
printf '%s' '%s\...
6
votes
2
answers
3k
views
What are the effects of double quotes in echo statements? [closed]
When writing a Bash script that contains messages for the user, I can write
echo Processing files...
or
echo "Processing files..."
In this and many other cases, the output will be the same....
3
votes
2
answers
7k
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 something ...
15
votes
6
answers
9k
views
Why there is such a difference in execution time of echo and cat?
Answering this question caused me to ask another question:
I thought the following scripts do the same thing and the second one should be much faster, because the first one uses cat that needs to open ...
2
votes
1
answer
2k
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.
8
votes
3
answers
89k
views
echo variable with content from 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 ...
5
votes
4
answers
3k
views
Echoing something with multiple quotes and key characters (&, $, !, etc.)
Let's say you have to echo this into a file:
RZW"a4k6[)b!^"%*X6Evf
How do you do it?
My actual "line" to echo is a 2048 characters line.
9
votes
7
answers
19k
views
echo \\* - bash backslash escape behavior, is it evaluated backwards?
So in bash,
When I do
echo \*
*
This seems right, as * is escaped and taken literally.
But I can't understand that,
when I do
echo \\*
\*
I thought the first backslash escaped the second one ...
3
votes
1
answer
116
views
Is there a difference between double quoting a variable or a whole line in echo
When you type, for example,
echo Variable "$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 ...
6
votes
2
answers
8k
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 ('MP1-Eq1')"}"...
81
votes
4
answers
205k
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 ...
34
votes
4
answers
168k
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 ...
14
votes
2
answers
8k
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 from ...
4
votes
1
answer
2k
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 ...
5
votes
2
answers
633
views
Why am I observing different behaviour of echo?
I 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
ronnie@ronnie:~$
So, can someone ...
33
votes
5
answers
145k
views
Why is echo ignoring my quote characters?
The echo command isn't including the complete text that I give it. For example, if I do:
$ echo ' echo PARAM=` grep $ARG /var/tmp/setfile | awk '{print $2}' ` '
It outputs:
echo PARAM=` ...