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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++...)

printf stand for print formatted. printf is shell builtin command used to print and format data and outputs to stdout.

In addition, many programming languages like awk, C++, PHP, perl use/include printf.

Useful links:

Example of usage on this site: Why printf is better than echo?

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Why is printf better than echo?

I have heard that printf is better than echo. I can recall only one instance from my experience where I had to use printf because echo didn't work for feeding some text into some program on RHEL 5.8 but printf did. But apparently, there are other…
amphibient
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Dashes in printf

I'm trying to use printf to format some pretty output in a bash script e.g.: ----------------------- | This is some output | ----------------------- But I've stumbled over some behavior I don't understand. $ printf "--" gives me the…
Kenny Rasschaert
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Why is printf "shrinking" umlaut?

If I execute the following simple script: #!/bin/bash printf "%-20s %s\n" "Früchte und Gemüse" "foo" printf "%-20s %s\n" "Milchprodukte" "bar" printf "%-20s %s\n" "12345678901234567890" "baz" It prints: Früchte und Gemüse foo Milchprodukte…
René Nyffenegger
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print output to 3 separate columns

MYPATH=/var/www/html/error_logs/ TOTALFILE=$(ls $MYPATH* | wc -l) FILETIME=$(stat --format=%y $MYPATH* | head -5 | cut -d'.' -f1) FILE=$(ls -1tcr $MYPATH* | head -5 | rev | cut -d/ -f1 | rev) TOPLINE=$(head -1 $MYPATH* | grep -Po '".*?"' | head…
ADM
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Awk printf number in width and round it up

I need to printf a number out, but with given width and rounded (with awk!) %10s I have this and somehow I need to connect the %d but everything I do, ends up with too much parametres for awk (because I have more columns).
Wanderer
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Using `printf` to print variable containing `%` percent sign results in "bash: printf: `p': invalid format character"

I want to use printf to print a variable. It might be possible that this variable contains a % percent sign. Minimal example: $ TEST="contains % percent" $ echo "${TEST}" contains % percent $ printf "${TEST}\n" bash: printf: `p': invalid format…
finefoot
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Why won't some unicode characters print to my terminal?

I'm running Arch Linux with simple terminal using the Adobe Source Code Pro font. My locale is correctly set to LANG=en_US.UTF-8. I want to print Unicode characters representing playing cards to my terminal. I'm using Wikipedia for reference. The…
Brian Fitzpatrick
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How to do formatted printing with jq?

jq has built-in ability to convert numbers to string or concatenate strings. How can I format strings inside jq similar to printf like padding (%4s). For example, how can I force number to occupy 10 char spaces with left alignment? echo '{"title" :…
Zeta.Investigator
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How do I stop Bash from interpreting octal code instead of integer?

I'm writing a a Horoscope RSS script as an intro to Unix/Linux project, and ran into an issue my Professor couldn't fix in the time I was able to stay after class. Since I couldn't figure out how to use actual dates as what to check, I thought I'd…
Irre Levant
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How do I capture stdin to a variable without stripping any trailing newlines?

In a shell script... How do I capture stdin to a variable without stripping any trailing newlines? Right now I have tried: var=`cat` var=`tee` var=$(tee) In all cases $var will not have the trailing newline of the input stream. Thanks. ALSO: If…
CommaToast
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Are there security consequences from not giving printf a format to use?

A well-formed printf usually has a format to use: $ var="Hello" $ printf '%s\n' "$var" Hello However, what could be the security implications of not providing a format? $ printf "$var" Hello As the variable expansion is quoted, there should not be…
user232326
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Only print output after finding pattern

There's a script (let's call it echoer) that prints to screen a bunch of information. I'd like to be able to only see lines after a pattern is found. I imagine the usage of a solution to look something like echoer | solution_command…
user23146
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Slightly confused about whether printf in the yash shell is a built-in command or not

The yash shell has a printf built-in, according to its manual. However, this is what I see in a yash shell with default configuration: $ command -v printf /usr/bin/printf $ type printf printf: a regular built-in at /usr/bin/printf Is printf a…
Kusalananda
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Padding trailing whitespaces in a string with another character

I'd like to output hello world over 20 characters. printf "%-20s :\n\n" 'hello world!!' # Actual output hello world!! : # Wanted output hello world!!========: However, I don't want to complete with spaces but with "=" instead. How do I do…
smarber
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bash + using printf in order to print in special format

I just wrote the following bash script to check the ping access on list of Linux machines: for M in $list do ping -q -c 1 "$M" >/dev/null if [[ $? -eq 0 ]] then echo "($C) $MACHINE CONNECTION OK" else echo "($C)…
yael
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