How do I avoid this unexpected behaviour when redirecting output from echo?
I wanted to add to my hosts file easily using a one line command, but I get an unexpected result.
$ sudo sh -c 'echo -e "10.0.10.0tserver.bananas.comtserver" >> /etc/hosts'
$ cat /etc/hosts
-e 10.0.10.0 server.bananas.com server
I'm using the -e switch on echo to enable the use of backslash escapes for the tabs, but the -e is being included in the redirected output.
How can I avoid this?
io-redirection echo
asked Dec 19 '18 at 3:25
paradroid
3781518
add a comment |
I wanted to add to my hosts file easily using a one line command, but I get an unexpected result.
$ sudo sh -c 'echo -e "10.0.10.0tserver.bananas.comtserver" >> /etc/hosts'
$ cat /etc/hosts
-e 10.0.10.0 server.bananas.com server
I'm using the -e switch on echo to enable the use of backslash escapes for the tabs, but the -e is being included in the redirected output.
How can I avoid this?
io-redirection echo
asked Dec 19 '18 at 3:25
paradroid
3781518
1
Yourshis likely a shell (such asdash) whoseechobuilt-in doesn't have a-eswitch
– steeldriver
Dec 19 '18 at 3:42
2
Related: Why is printf better than echo?
– steeldriver
Dec 19 '18 at 3:44
add a comment |
I wanted to add to my hosts file easily using a one line command, but I get an unexpected result.
$ sudo sh -c 'echo -e "10.0.10.0tserver.bananas.comtserver" >> /etc/hosts'
$ cat /etc/hosts
-e 10.0.10.0 server.bananas.com server
I'm using the -e switch on echo to enable the use of backslash escapes for the tabs, but the -e is being included in the redirected output.
How can I avoid this?
io-redirection echo
asked Dec 19 '18 at 3:25
paradroid
3781518
I wanted to add to my hosts file easily using a one line command, but I get an unexpected result.
$ sudo sh -c 'echo -e "10.0.10.0tserver.bananas.comtserver" >> /etc/hosts'
$ cat /etc/hosts
-e 10.0.10.0 server.bananas.com server
I'm using the -e switch on echo to enable the use of backslash escapes for the tabs, but the -e is being included in the redirected output.
How can I avoid this?
io-redirection echo
io-redirection echo
asked Dec 19 '18 at 3:25
paradroid
3781518
asked Dec 19 '18 at 3:25
paradroid
3781518
asked Dec 19 '18 at 3:25
paradroid
3781518
asked Dec 19 '18 at 3:25
paradroid
3781518
asked Dec 19 '18 at 3:25
paradroid
3781518
3781518
1
Yourshis likely a shell (such asdash) whoseechobuilt-in doesn't have a-eswitch
– steeldriver
Dec 19 '18 at 3:42
2
Related: Why is printf better than echo?
– steeldriver
Dec 19 '18 at 3:44
add a comment |
1
Yourshis likely a shell (such asdash) whoseechobuilt-in doesn't have a-eswitch
– steeldriver
Dec 19 '18 at 3:42
2
Related: Why is printf better than echo?
– steeldriver
Dec 19 '18 at 3:44
1
1
Your
sh is likely a shell (such as dash) whose echo built-in doesn't have a -e switch– steeldriver
Dec 19 '18 at 3:42
Your
sh is likely a shell (such as dash) whose echo built-in doesn't have a -e switch– steeldriver
Dec 19 '18 at 3:42
2
2
Related: Why is printf better than echo?
– steeldriver
Dec 19 '18 at 3:44
Related: Why is printf better than echo?
– steeldriver
Dec 19 '18 at 3:44
add a comment |
1 Answer
1
active
oldest
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I'm not exactly sure why echo is failing as per your question, but in general, I'd use printf instead. It's much more predictable in its output.
printf '%st%st%sn' '10.0.10.0' 'server.bananas.com' 'server'
Explanation
%st%st%sn: this part explains what the output format will be, i.e. a string, a tab, a string, a tab, a string, a newline.- The three strings are the following arguments supplied to
printf.
Writing to root-owned files
Also, I'm not sure if you are aware, but instead of using the sudo sh -c construct, you could use sudo tee instead. i.e.
printf … | sudo tee -a /etc/hosts
I find this more convenient, especially when it avoids having to escape characters inside the external '.
answered Dec 19 '18 at 3:29
Sparhawk
9,27363991
add a comment |
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I'm not exactly sure why echo is failing as per your question, but in general, I'd use printf instead. It's much more predictable in its output.
printf '%st%st%sn' '10.0.10.0' 'server.bananas.com' 'server'
Explanation
%st%st%sn: this part explains what the output format will be, i.e. a string, a tab, a string, a tab, a string, a newline.- The three strings are the following arguments supplied to
printf.
Writing to root-owned files
Also, I'm not sure if you are aware, but instead of using the sudo sh -c construct, you could use sudo tee instead. i.e.
printf … | sudo tee -a /etc/hosts
I find this more convenient, especially when it avoids having to escape characters inside the external '.
answered Dec 19 '18 at 3:29
Sparhawk
9,27363991
add a comment |
I'm not exactly sure why echo is failing as per your question, but in general, I'd use printf instead. It's much more predictable in its output.
printf '%st%st%sn' '10.0.10.0' 'server.bananas.com' 'server'
Explanation
%st%st%sn: this part explains what the output format will be, i.e. a string, a tab, a string, a tab, a string, a newline.- The three strings are the following arguments supplied to
printf.
Writing to root-owned files
Also, I'm not sure if you are aware, but instead of using the sudo sh -c construct, you could use sudo tee instead. i.e.
printf … | sudo tee -a /etc/hosts
I find this more convenient, especially when it avoids having to escape characters inside the external '.
answered Dec 19 '18 at 3:29
Sparhawk
9,27363991
add a comment |
I'm not exactly sure why echo is failing as per your question, but in general, I'd use printf instead. It's much more predictable in its output.
printf '%st%st%sn' '10.0.10.0' 'server.bananas.com' 'server'
Explanation
%st%st%sn: this part explains what the output format will be, i.e. a string, a tab, a string, a tab, a string, a newline.- The three strings are the following arguments supplied to
printf.
Writing to root-owned files
Also, I'm not sure if you are aware, but instead of using the sudo sh -c construct, you could use sudo tee instead. i.e.
printf … | sudo tee -a /etc/hosts
I find this more convenient, especially when it avoids having to escape characters inside the external '.
answered Dec 19 '18 at 3:29
Sparhawk
9,27363991
I'm not exactly sure why echo is failing as per your question, but in general, I'd use printf instead. It's much more predictable in its output.
printf '%st%st%sn' '10.0.10.0' 'server.bananas.com' 'server'
Explanation
%st%st%sn: this part explains what the output format will be, i.e. a string, a tab, a string, a tab, a string, a newline.- The three strings are the following arguments supplied to
printf.
Writing to root-owned files
Also, I'm not sure if you are aware, but instead of using the sudo sh -c construct, you could use sudo tee instead. i.e.
printf … | sudo tee -a /etc/hosts
I find this more convenient, especially when it avoids having to escape characters inside the external '.
answered Dec 19 '18 at 3:29
Sparhawk
9,27363991
answered Dec 19 '18 at 3:29
Sparhawk
9,27363991
answered Dec 19 '18 at 3:29
Sparhawk
9,27363991
answered Dec 19 '18 at 3:29
Sparhawk
9,27363991
9,27363991
add a comment |
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1
Your
shis likely a shell (such asdash) whoseechobuilt-in doesn't have a-eswitch– steeldriver
Dec 19 '18 at 3:42
2
Related: Why is printf better than echo?
– steeldriver
Dec 19 '18 at 3:44