Linked Questions

46
votes
6answers
102k views

Difference between printf and echo in bash [duplicate]

What is the difference between the printf function in bash and the echo function? Specifically, running: echo "blah" >/dev/udp/localhost/8125 did not send the "blah" command to the server ...
0
votes
0answers
43 views

Avoiding echo -e [duplicate]

I would like to store an HTTP request in a variable and then use it with OpenSSL I now have HTTP_REQUEST="HEAD / HTTP/1.1\\nHost: ${HOST_HEADER}\\nUser-Agent: check_ssl_cert/${VERSION}\\nConnection: ...
562
votes
5answers
201k views

What does “--” (double-dash) mean?

I have seen -- used in the compgen command. For example: compgen -W "foo bar baz" -- b What is the meaning of the -- in there?
97
votes
18answers
246k views

How to count the number of a specific character in each line?

I was wondering how to count the number of a specific character in each line by some text processing utilities? For example, to count " in each line of the following text "hello!" Thank you! The ...
68
votes
8answers
88k views

How to delete line with echo?

I know that I could delete the last three chars with: echo -ne '\b\b\b' But how can I delete a full line? I mean I don't want to use: echo -ne '\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\...
29
votes
15answers
56k views

'ls -1' : how to list filenames without extension

ls -1 lists my elements like so: foo.png bar.png foobar.png ... I want it listed without the .png like so: foo bar foobar ... (the dir only contains .png files) Can somebody tell me how to use ...
55
votes
9answers
167k views

Can sed replace new line characters?

Is there an issue with sed and new line character? I have a file test.txt with the following contents aaaaa bbbbb ccccc ddddd The following does not work: sed -r -i 's/\n/,/g' test.txt ...
51
votes
8answers
196k views

How to add new lines when using echo

Why does the following command not insert 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
65
votes
6answers
168k views

Concatenating two variables with an underscore

I need to concatenate two variables to create a filename that has an underscore. Lets call my variables $FILENAME and $EXTENSION where filename is read from a file. FILENAME=Hello EXTENSION=WORLD.txt ...
52
votes
5answers
216k views

Redirecting the content of a file to the command “echo”

I have a file named my_file.txt whose content is just the string Hello. How could I redirect its content to the command echo? I know I have the commands less, cat, more... but I need to do it with ...
26
votes
8answers
3k views

Is piping, shifting, or parameter expansion more efficient?

I'm trying to find the most efficient way to iterate through certain values that are a consistent number of values away from each other in a space separated list of words(I don't want to use an array)....
8
votes
5answers
4k views

How to list *.tar.gz, one filename per line?

I am trying to list every .tar.gz file, only using the following command: ls *.tar.gz -l ...It shows me the following list: -rw-rw-r-- 1 osm osm 949 Nov 27 16:17 file1.tar.gz -rw-rw-r-- 1 osm osm ...
42
votes
2answers
49k views

Difference between 'echo' and 'echo -e' [closed]

What is the difference between echo and echo -e? Which quotes (" " or ' ')should be used with the echo command? ie: echo "Print statement" or echo 'Print statement'? Also, what are the available ...
22
votes
6answers
2k views

Is there another simple way to append line to end of file other than `>>`?

Recently I'm echoing short sentences to a tree_hole file. I was using echo 'something' >> tree_hole to do this job. But I was always worried of what if I mis-input of > instead of >>, ...
19
votes
4answers
129k views

How do I echo a string with multiple spaces in bash “untouched”? [duplicate]

I assigned a var like this: MYCUSTOMTAB=' ' But using it in echo both: echo $MYCUSTOMTAB"blah blah" or echo -e $MYCUSTOMTAB"blah blah" just returns a single space and the rest of the string: ...

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