Questions tagged [printf]
The shell builtin command that formats and prints data. Questions that deal with printf command or broadly using printf syntax by programming language (like awk, PHP, perl, C++...)
282
questions
5
votes
1
answer
209
views
printf in Zsh does not shell escape exclamation mark
In Zsh 5.9, we can use printf to shell escape a string:
$ printf '%q' 'One! Two'
One\!\ Two
This produces the correct output of escaping the ! and the space. Now let’s make it as a script:
#!/bin/...
- 559
7
votes
1
answer
587
views
printf - store formatted string output in a variable
Instead of the following
printf '%s\t%s\t%s\t%s\n' 'index' 'podcast' 'website' 'YouTube'
I want to store the printf output in a Results variable, how can I do this?
- 2,056
0
votes
1
answer
42
views
How do I pass hex characters to printf in a script command? [duplicate]
How do I get printf to output hex characters when run from a script?
Suppose I am at the prompt and type printf "\x41\x42" the output I get
AB%
However if I have a script containing that ...
- 125
2
votes
1
answer
104
views
Why does printing an array with @ using printf in bash only print the first element?
I have an array
snapshots=(1 2 3 4)
When I run
printf "${snapshots[*]}\n"
It prints as expected
1 2 3 4
But when I run
printf "${snapshots[@]}\n"
It just prints
1
without a ...
- 163
0
votes
1
answer
158
views
List all files in a directory, recursively, sorted by modification date
The main answer of Sort the files in the directory recursively based on last modified date gives a method to list all files in a directory, recursively, sorted by modification date:
find -printf "...
- 2,549
0
votes
0
answers
16
views
How to preserve updating output in pipe, e.g. when output has `\r`
Whenever I pipe some output that is updating (say with \r), e.g. to a pager (less), or to colourise parts of it, the pipe seems to drop the lines that are updating. Any idea how to preserve the ...
- 150
2
votes
1
answer
145
views
Print Variable containing backslashes
I have something like this:
A=$(curl https://mysite.com)
and the curl request returns the string \"Hello World\".
When I now want to print A to the console using one of:
echo "$A"
...
- 31
2
votes
1
answer
294
views
"ls" counterpart to "find" operator "-printf"?
The find command has a handy -printf operator that prints
user-specified metadata for each found file/folder. Is there such an
option for the ls command?
As an alternative, I can feed the list of ...
- 427
-1
votes
1
answer
150
views
Why does printf not round numbers the way I expect in my bash? [duplicate]
prompt> printf "%.2f\n" 3.314
3.31
prompt> printf "%.2f\n" 3.315
3.32
This is fine, I got what I wanted. However if I use different numbers, I get this:
prompt> printf &...
- 202
0
votes
2
answers
189
views
Why might I want to avoid such echo-like way of using `printf` when printing to stdout? [duplicate]
I wrote the following script when trying to understand how printf works:
#!/usr/bin/bash
printf "Give me your three preferences.?
"
read p1
read p2
read p3
printf "%s\n" "${...
- 785
0
votes
0
answers
46
views
How to pass a binary number to printf? [duplicate]
Such a silly question but I've been trying for at least 15 minutes already and it's late at night. How to use printf in bash to convert a binary number to hex? Here's what I've tried:
$ printf %x 11 ...
- 3,115
0
votes
2
answers
326
views
Bash and other shells $(...) remove the ending newline character [duplicate]
Why the shell structure $(...) removes the ending newline character?
#!/bin/bash
S='a
b
'
printf '%i [%s]\n' "${#S}" "$S"
T=$(printf '%s' "$S")
printf '%i [%s]\n' "...
- 147
0
votes
1
answer
22
views
how to write a commant for output of a particular group?
Reading file prod1.tpr, VERSION 2019.6 (single precision)
Reading file prod1.tpr, VERSION 2019.6 (single precision)
Select a group of reference atoms and a group of molecules to be ordered:
Group ...
0
votes
1
answer
111
views
Flush output continuously with xargs
The function output the size of the downloaded file and the speed of transfer separated with newline.
Example:
20 #<< data
3.0M #<< speed
25
1.2M
Now, it goes like this:
output_data_func |...
- 312
2
votes
2
answers
309
views
Why does awk concatenate strings from different lines
Good day.
I'm trying to run a ping6 on IPv6 addresses pulled from /etc/resolv.conf.dnsph. It seems though, as if awk is stringing the IPv6 addresses onto one line.
$ grep ^nameserver /etc/resolv.conf....
- 31