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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 "\*" ...
Christopher Lee's user avatar
4 votes
2 answers
647 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 ...
finefoot's user avatar
  • 3,132
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 ...
quester's user avatar
  • 293
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 ...
Viesturs's user avatar
  • 943
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 ...
Viktor's user avatar
  • 251
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
tmpbin's user avatar
  • 783
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 ...
RKA's user avatar
  • 877
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 ...
Zeruno's user avatar
  • 153
7 votes
2 answers
882 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 ...
csirac2's user avatar
  • 171
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 ...
Rafaf Tahsin's user avatar
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\...
George's user avatar
  • 545
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....
Chad's user avatar
  • 1,471
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 ...
Proletariat's user avatar
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 ...
Mohammad's user avatar
  • 688
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.
Jake's user avatar
  • 1,373

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