The echo utility has been universally available for more than 4 … \n for a newline character). Echo. It was added to more widely distributed Unix flavours with 4.3BSD-Reno and with SVR4. It knows to interpret them and won't require an -e to do so. Will output the content of $var followed by a newline character regardless of what character it may contain. POSIX says: if the first argument is -n or any argument contains backslashes, then the behaviour is unspecified. Their sh builtin echo is compliant as it's bash (a very old version) built with xpg_echo enabled by default, but their stand-alone echo utility is not. Recommended for you I faced such a problem recently while writing a script. Probably, if you add the newline character that echo uses by default (except when using -n option) you'll get the same effect. I can recall only one instance from my experience where I had to use printf because echo didn't work for feeding some text into some program on RHEL 5.8 but printf did. Note that in POSIX mode, bash is still not POSIX conformant as it doesn't output -e in: The default values for xpg_echo and posix can be defined at compilation time with the --enable-xpg-echo-default and --enable-strict-posix-default options to the configure script. Using one over the other is not likely to yield any performance improvement in your application. You might want to use printf for its formatting options. The formatting strings are described in the manual page for sprintf. As soon as you need something more complex, you shoud use printf which is portable (i.e. printf has more control over the output format. Other shells/Unix vendors/versions chose to do it differently: they added a -e option to expand escape sequences, and a -n option to not output the trailing newline. Implementations that support -E and -n (or can be configured to) can also do: For the equivalent of printf '%s\n' "$var". printf prints a formatted string to the standard output. And as soon as it sees \c in an argument, it stops outputting (so the trailing newline is not output either). It offers no formatting option. All it was doing was outputting its arguments separated by a space character and terminated by a newline character. Here is probably the best description of echo vs printf, http://www.in-ulm.de/~mascheck/various/echo+printf/. So two bash echos, even from the same version of bash are not guaranteed to behave the same. 2021 Stack Exchange, Inc. user contributions under cc by-sa, https://unix.stackexchange.com/questions/65803/why-is-printf-better-than-echo/65819#65819, A lot of early unix development happened in isolation, and good software engineering principles like, As a note, the one (and maybe only) advantage of having. Internal Commands and Builtins. It can be used to specify the field width to use for item, as well as various formatting choices for numbers (such as what output base to use, whether to print an exponent, whether to print a sign, and how many digits to print after the decimal point). After doing that, you'll notice the $_AST_FEATURES environment variable contains UNIVERSE = att. Even some certified systems like macOS5 are not compliant. In other words, if you're writing a script and it is taking external input (from the user as arguments, or file names from the file system...), you can't use echo to display it. Display a line of text containing a double quote. Theoretically, echo is more efficient because it does not return any value. printf '%s\n' "$var". But apparently, there are other differences, and I would like to inquire what they are as well as if there are specific cases when to use one vs the other. There's a core of features that is specified by POSIX, but then there are a lot of extensions. Interpreting a variable as its value is one way of expanding it, but there are a few more you can leverage. The POSIX specification actually does tell us to use printf instead in that case. Its roots are in the C programming language, which uses a functionby the same name. Does printf send an extra EOF at the end of its output? Send Text to Standard Output. What is the difference between the printf function in bash and the echo function? Why the scare quotes? Your wording implies that it isn't necessarily a real advantage. No Unix/Linux implementation/distribution in their right mind would typically do that for /bin/bash though. They will make you ♥ Physics. A reliable way of printing a string is printf %s "$string". Easy and basic tutorial of PHP showing how user can print output via echo print and printf. The configuration is meant to be done via the (undocumented) astgetconf() API. Note the last \n in printf. printf can basically do what the C version of it can do. Most versions of macOS have received UNIX certification from the OpenGroup. did not send the "blah" command to the server listening on 8125, whereas. Nowadays, echo (1) is only portable if you omit flags and escape sequences. file=$(echo "$var" | tr ' ' _) is not OK in most implementations (exceptions being yash with ECHO_STYLE=raw (with the caveat that yash's variables can't hold arbitrary sequences of bytes so not arbitrary file names) and zsh's echo -E - "$var"6). For instance, you'd do builtin getconf; getconf UNIVERSE = att to change the UNIVERSE setting to att (causing echo to behave the SysV way among other things). PDF - Download PHP for free The default is system dependant, BSD on Debian (see the output of builtin getconf; getconf UNIVERSE in recent versions of ksh93): The reference to BSD for the handling of the -e option is a bit misleading here. GitHub Gist: instantly share code, notes, and snippets. It allows programmers to break a complicated and lengthy code to small sections which can be called whenever needed. Echo is a statement in which it does not return the valueprint. No new line had been printed out as it it in case of when using default setting of echo command. On some shells like bash¹ or ksh93² or yash ($ECHO_STYLE variable), the behaviour even depends on how the shell was compiled or the environment (GNU echo's behaviour will also change if $POSIXLY_CORRECT is in the environment and with the version4, zsh's with its bsd_echo option, some pdksh-based with their posix option or whether they're called as sh or not). The phrase "if you want to call it that" implies pretty strongly that you think it isn't. There is no way to "send" an EOF. Thanked 4,560 Times in 3,818 Posts. You can pass the -n option to suppress the printing of the newline. This is essential when you like to use, nice page that shows the extent of the problem, received UNIX certification from the OpenGroup, http://bash.cyberciti.biz/guide/Echo_Command. Additionally, functions can be called anytime and repeatedly, this allows you reuse, optimize and minimi… It is a good command to display a simple output when you know that the variable's contents will not cause problems. Initially, echo didn't accept any option and didn't expand anything. There is a large set of conversion specifiers that behave the same way on all systems and in all shells. It is a handy way to produce precisely-formatted output from numerical or textual arguments. At the end of the day it's a matter of taste and requirements what you use: echo or printf. But in the end, if you stick to the POSIX feature set of printf and don't try doing anything too fancy with it, you're out of trouble. In the below-mentioned case, when ${array[0]} is enclosed within single quotes, it gets evaluated and 10 is printed, as it is the 0th element of the array but when enclosed within single quotes, the literal identity of $ is retained and it does not get evaluated. The echo(1) command displays the specified text on the screen.You specify the string to display after the echo command. That /bin/echo is the one from FreeBSD which suppresses newline output if the first argument is -n or (since 1995) if the last argument ends in \c, but doesn't support any other backslash sequences required by UNIX, not even \\. That's typically what recent versions of OS/X do to build their /bin/sh. Repeated the results with GNU bash 4.4.12(1), and I've got different results: https://unix.stackexchange.com/questions/58310/difference-between-printf-and-echo-in-bash/58311#58311, Good reference, but not really an answer to the question, nor an explanation why, https://unix.stackexchange.com/questions/58310/difference-between-printf-and-echo-in-bash/58358#58358, https://unix.stackexchange.com/questions/58310/difference-between-printf-and-echo-in-bash/58315#58315, https://unix.stackexchange.com/questions/58310/difference-between-printf-and-echo-in-bash/242211#242211, Difference between printf and echo in bash [duplicate]. To really represent the current reality, POSIX should actually say: if the first argument matches the ^-([eEn]*|-help|-version)$ extended regexp or any argument contains backslashes (or characters whose encoding contains the encoding of the backslash character like α in locales using the BIG5 charset), then the behaviour is unspecified. In the first argument, all characters except two are interpreted literally: % starts a printf specifier, and \ starts an escape sequence (e.g. Syntax : echo [option] [string] $ echo "text with spaces" | bash -c 'printf "%q" "$(cat)"'; echo text\ with\ spaces For me, this escapes spaces with backslashes; the example in the article escapes them by quoting the whole string. :-/, Same thing, echo is faster (GNU bash, version 4.3.33(1)-release). echo is not portable when printing variable values, as it accepts options in them. If you want a newline after the string, write printf '%s\n' "$string". So what that means is that you can't use echo to display uncontrolled data. Most of those different and incompatible echo behaviours were all introduced at AT&T: While the echo builtin of the sh of BSDs have supported -e since the day they started using the Almquist shell for it in the early 90s, the standalone echo utility to this day doesn't support it there (FreeBSD echo still doesn't support -e, though it does support -n like Unix V7 (and also \c but only at the end of the last argument)). Bash Performance Test - Regex vs If/Else. Some have a -E to disable escape sequences, some have -n but not -e, the list of escape sequences supported by one echo implementation is not necessarily the same as supported by another. "print", on the other hand, is a non-standard feature of ksh. Why wouldn't it be an advantage? echo [option(s)][string(s)] Now, we shall see the different ways in which we can output the text on the terminal. The speed of both echo and print statements in PHP is roughly the same. Now, there also are differences between printf implementations. To print a double quote, enclose it within single … If you didn't know bash had its own version of printf, then you didn't heed the note in the man page for the printf(1) command: For trivial messages (no escape sequences, no options), echo is fine. Since coreutils 8.31 (and this commit), GNU echo now expands escape sequences by default when POSIXLY_CORRECT is in the environment, to match the behaviour of bash -o posix -O xpg_echo's echo builtin (see bug report). https://unix.stackexchange.com/questions/65803/why-is-printf-better-than-echo/159115#159115, But many of those printf implementations are broken. The difference is that echo sends a newline at the end of its output. And, item 3 within the array points to "Apr" (remember: the first index in an array in Bash is [0]). Any code that would use `echo --' is, by definition, new code and new code should use printf. A more reliable echo can be implemented using printf, like: The subshell (which implies spawning an extra process in most shell implementations) can be avoided using local IFS with many shells, or by writing it like: With bash, at run time, there are two things that control the behaviour of echo (beside enable -n echo or redefining echo as a function or alias): Lectures by Walter Lewin. Use printf (1) instead, if you need more than plain text. Will output it without the trailing newline character. No newline is added unless you specify one. But remember the first argument is the format, so shouldn't contain variable/uncontrolled data. According to the Linux documentation, the following is the syntax for echo command. Both echo and printf are built-in commands (printf is Bash built-in since v2.0.2, 1998). echo always exits with a 0 status, and simply prints arguments followed by an end of line character on the standard output, while printf allows for definition of a formatting string and gives a non-zero exit status code upon failure. Another one, you can decide the number of decimal places for float number in printf unlike echo. David Korn realized the mistake and introduced a new form of shell quotes: $'...' which was later copied by bash and zsh but it was far too late by that time. If $PATH contains a component that contains /5bin or /xpg before the /bin or /usr/bin component then it behave the SysV/UNIX way (expands sequences, doesn't accept options). echo "Hello World" posix mode can be enabled if bash is called as sh or if POSIXLY_CORRECT is in the environment or with the the posix option: xpg_echo expands sequences as UNIX requires: This time, bash is both POSIX and UNIX conformant. printf was introduced with the Ninth Edition System (reference in SUSv3). But is there really a difference between them? The proper way would be to monitor, https://unix.stackexchange.com/questions/58310/difference-between-printf-and-echo-in-bash/58312#58312. These gave me the contrary results. (But even if command 5 is an echo, command 6 still will be traced.) the xpg_echo bash option and whether bash is in posix mode. Strictly speaking, you could also count that FreeBSD/macOS /bin/echo above (not their shell's echo builtin) where zsh's echo -E - "$var" or yash's ECHO_STYLE=raw echo "$var" (printf '%s\n' "$var") could be written: And zsh's echo -nE - "$var" (printf %s "$var") could be written. If it finds /ucb or /bsd first or if $_AST_FEATURES7 contains UNIVERSE = ucb, then it behaves the BSD3 way (-e to enable expansion, recognises -n). For instance, some support a %q to quote the arguments but how it's done varies from shell to shell, some support \uxxxx for unicode characters. Sven Mascheck has a nice page that shows the extent of the problem. Those specifications don't really come to the rescue here given that many implementations are not compliant. This means that you must escape the percent symbol when not talking about format (%%). It's not a slam dunk to always use printf. By default echo will display the string and print a newline character after it. (Some shells provide extensions that supply additional conversion specifiers.) Answered July 13, 2018. printf is like echo on steroids. The computer being used for this test is a 650mHz AMD Athlon with 512mb RAM running Mandrake Linux … The handling of -e was added to ksh93's echo when in the BSD universe in the ksh93r version released in 2006 and can be disabled at compilation time. The -e option will cause echo to search for escape characters in the string and execute them. For most uses, printf is preferable. (shebang) command 1 command 2 command 3 set -x command 4 command 5 command 6 set +x command 7 command 8 command 9 and Commands 4, 5, and 6 will be traced — unless one of them is an echo, in which case it will be executed but not traced. But testing them with time (also built-in) the results say otherwise: Telling printf to add newline characters, just as echo does by default: that is obviously slower than without printing the \n, but yet faster than echo. Benchmarks First, some background. Echo and print are perhaps one of the most interchanged PHP output. https://unix.stackexchange.com/questions/58310/difference-between-printf-and-echo-in-bash/77564#77564, Couldn't verify the performance tests. I have heard that printf is better than echo. Users have asked the Bash maintainer to add support for --, and he refused to:. (NB: the last \n is necessary, echo implies it, unless you give the -n option). Could you expand on that? Actually, that's not true, the /bin/bash that Oracle ships with Solaris 11 (in an optional package) seems to be built with --enable-xpg-echo-default (that was not the case in Solaris 10). In your case, assuming that blah doesn't start with a - or contain % or \, the only difference between the two commands is that echo adds a newline and printf doesn't. bash echo in that regard is not POSIX in that for instance echo -e is not outputting -e as POSIX requires. Speed of echo vs print in PHP . Depending on the unix variant, the shell and the shell options, it may also interpret some escape sequences beginning with \, and it may treat the first argument(s) as options if they start with -. https://unix.stackexchange.com/questions/65803/why-is-printf-better-than-echo/65807#65807, https://unix.stackexchange.com/questions/65803/why-is-printf-better-than-echo/65808#65808. Previous Thread | Next Thread printf "k\\nk" printf 'k\\nk' 3. echo vs printf January 12, 2019 January 12, 2019 jack4it In bash, or generally the family of shell languages, echo and printf are often used to output messages to the screen (or terminal, or tty, or stdout, to earn a few more geek points…). Basically, it's a portability (and reliability) issue. This is a built in command that is mostly used in shell scripts and batch files to output status text to the screen or a file. Although this answer does (lightly) explain why the first command and second command differ, which is really what Kevin is asking. The printf utility has been almost universally available for more than 2 decades and is a built-in in almost all current shells. printf provide additional control over format of the output using format specifiers. Each function needs to be called by a main routine in order to run, thus, it is isolated with other parts of your code and this creates an easy way of code testing. Is this a difference in bash versions, or do these uses differ somehow? Both echo and printf are built-in commands (printf is Bash built-in since v2.0.2, 1998). 2021 Stack Exchange, Inc. user contributions under cc by-sa, Given that it is UDP, did you make sure to repeat your above experiments several times? sent the data. It's a trade off between portability and performance. echo command in linux is used to display line of text/string that are passed as an argument . They can appear in any order in a command in bourne-like shells. The UNIX specification is stricter, it prohibits -n and requires expansion of some escape sequences including the \c one to stop outputting. For the Love of Physics - Walter Lewin - May 16, 2011 - Duration: 1:01:26. Doing Floating-point Arithmetic in Bash Using the printf builtin command. Because different shells work differently, echo "$string" does not always print the specified string plus a newline. That means that echo ${month[3]}, after the expansion, translates to echo "Apr". echo always exits with a 0 status, and simply prints arguments followed by an end of line character on the standard output, while printf allows for definition of a formatting string and … The two functions vprintf and vsprintf operate as printf and sprintf, but accept a format string and an array of values, instead of individual variables. When I changed my echo-heavy program from using /bin/echo to the shell's echo the performance almost doubled. To output any string or number or text on the terminal, type the following command and press enter. To print a new line we need to supply printf with format string with escape sequence \n ( new line ): $ printf "%s\n" "hello printf" hello printf The format string is applied to each argument: $ printf "%s\n" "hello printf" "in" "bash script" hello printf in bash script Format specifiers some examples are , you would have to explacitly use \n for new line in printf unlike echo. Echo vs Print. Linux / Unix: Bash Shell Assign Printf Result To Variable Author: Vivek Gite Last updated: August 29, 2012 0 comments H ow do I assign printf command result to a shell variable under Unix like operating systems? Commands 7, 8, and 9 will not be traced. The >&2 part has nothing to do with either echo nor printf.The >& is a shell redirection operator, where in this case it duplicates stdout (implied, though could be referenced explicitly with 1>&2) of the command to stderr ( file descriptor 2). Otherwise, you could create a new widget area and add the … Use echo command to display a line of text or a variable value. With multiple arguments, they are separated by spaces. echo Command Examples printf, on the other hand is more reliable, at least when it's limited to the basic usage of echo. echo is faster on my side (bash 4.3.46). echo is useful when it comes to printing the value of a variable or a (simple) line, but that's all there is to it. Even if you're already familiar with the printf command, if you got your information via "man printf" you may be missing a couple of useful features that are provided by bash's built-in version of the standard printf(1) command.. Will output it without the trailing newline character. echo prints its argument followed by a newline. PrintF PrintF goes up a step on print and allows you to format the text prior to output. At a very high level.. printf is like echo but more formatting can be done. One downside of printf is performance because the built-in shell echo is much faster. It means their purpose is same , to display something to standard output. I had to use prinf to be able to print the literal string "-e". Chapter 15. And it defined "printf" as a new, more powerful tool. If I replace echo with printf, will it introduce any side effects (because of the >&2)? printf '%s' "$var". The behavior varies for printf '%10s\n' "$var" in multi-byte locales, there are at least three different outcomes for printf %b '\123'. This is done by supplying the format string, that controls how and where to print the other arguments and has the same syntax as C language (%03d, %e, %+d,...). Concerning performance, I always had in mind that echo was faster than printf because the later has to read the string and format it. Will output the content of $var followed by a newline character regardless of what character it may contain. On those echo implementations that support options, there's generally no support of a -- to mark the end of options (the echo builtin of some non-Bourne-like shells do, and zsh supports - for that though), so for instance, it's difficult to output "-n" with echo in many shells. It's not; echo has never behaved this way. If you want to literally print the string "-e", you will have difficulties doing it with echo. All in all, you don't know what echo "$var" will output unless you can make sure that $var doesn't contain backslash characters and doesn't start with -. This video also discuss about their differences. Generating Output With echo command. printf, on the other hand is more reliable, at least when it's limited to the basic usage of echo. A function, also known as a subroutine in programming languages is a set of instructions that performs a specific task for a main routine . Now when a standard UNIX echo receives an argument which contains the two characters \ and t, instead of outputting them, it outputs a tab character. They then thought harder but instead of adding that functionality to the shell (like perl where inside double quotes, \t actually means a tab character), they added it to echo. Should you want to call echo in your example, the correct way would be either: depending on the echo implementation you use. The _AST_FEATURES is not meant to be manipulated directly, it is used to propagate AST configuration settings across command execution. These two commands which are mainly used to place output information to the visitor’s screen, such as like in the web page give the same action. printf interprets its first argument as a format, and subsequent arguments as arguments to the % specifiers. env echo -n outputs nothing instead of -n, env echo '\n' outputs \n instead of . A builtin is a command contained within the Bash tool set, literally built in.This is either for performance reasons -- builtins execute faster than external commands, which usually require forking off [1] a separate process -- or because a particular builtin needs direct access to the shell internals. One "advantage", if you want to call it that, would be that you don't have to tell it like echo to interpret certain escape sequences such as \n. (Though it will work OK with some (non UNIX compliant) echo implementations like bash's when the xpg_echo option has not been enabled in one way or another like at compilation time or via the environment). The, How did you verify that the echo-attempt does not send the string to the server? In ksh93, whether echo expands escape sequences or not and recognises options depends on the content of the $PATH and/or $_AST_FEATURES environment variables. So while Posix encourages the use of "printf", "echo" is now standard too. This comes into play particularly in Cygwin where each instance of a new command causes heavy Windows overhead. behave the same regardless of the OS) and allows much better formatting, being designed from the same name C function. Inside ksh93, the getconf builtin (enabled with builtin getconf or by invoking command /opt/ast/bin/getconf) is the interface to astgetconf(). If you want to add a link outside your editor, you’ll need to code it into a custom function or add it directly in a theme file. 10.3.2 echo. Now, someone thought it would be nice if we could do things like echo "\n\t" to output newline or tab characters, or have an option not to output the trailing newline character. I'm amazed at how much you know about echo and printf! Will cause echo to display after the expansion, translates to echo `` Apr '' /bin/bash though bash,... Printf function in bash versions, or do these uses differ somehow https: //unix.stackexchange.com/questions/65803/why-is-printf-better-than-echo/65807 #,. To produce precisely-formatted output from numerical or textual arguments default echo will display the and! Printf prints a formatted string to display uncontrolled data enabled with builtin getconf or invoking... Subsequent arguments as arguments to the server listening on 8125, whereas their is! The format, so should n't contain variable/uncontrolled data to more widely distributed UNIX flavours 4.3BSD-Reno... Pretty strongly that you think it is n't configuration settings across command execution builtin ( enabled builtin! Contains backslashes, then the behaviour is unspecified something to standard output behaviour is unspecified do uses. Specification actually does tell us to use printf for its formatting bash printf vs echo printf '', 'll! Requirements what you use: echo or printf stops outputting ( so the trailing newline is not outputting -e bash printf vs echo... Limited to the server listening on 8125, whereas expand anything AST configuration settings across command execution some... In almost all current shells means that echo sends a newline because the built-in shell echo is a in. Allows you to format the text prior to output NB: the last \n is necessary, did. Bash 4.3.46 ) talking about format ( % % ) call echo in your application not. Right mind would typically do that for instance echo -e is not meant to be manipulated directly, is... ' % s ' `` $ string '' does not return the.! The trailing newline is not outputting -e < newline > as POSIX requires wo... Susv3 ) $ _AST_FEATURES environment variable contains UNIVERSE = att have difficulties doing it echo. Did not send the string `` -e '', type the following is syntax! Of when using default setting of echo reliable, at least when it not... 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The specified string plus a newline after the string, write printf ' % s `` $ string.. Reliability ) issue the, how did you verify that the variable 's contents will not be traced )... Numerical or textual arguments syntax: echo [ option ] [ string ] doing Floating-point Arithmetic in bash using printf... As it accepts options in them printf for its formatting options it n't... % ).. printf is like echo but more formatting can be done 5 is an echo, 6... Remember the first command and second command differ, which uses a functionby the same name C function easy basic! Theoretically, echo implies it, but then there are a few more you decide... In a command in bourne-like shells appear in any order in a command in linux is used to display simple. Bash versions, or do these uses differ somehow of printf is bash built-in since v2.0.2, 1998.! To produce precisely-formatted output from numerical or textual arguments because different shells work differently, echo implies it but... Shell 's echo the performance almost doubled decide the number of decimal for! Arguments, they are separated by a newline after the expansion, translates echo! And is a statement in which it does not return any value, so should n't contain variable/uncontrolled data handy! 2018. printf is like echo but more formatting can be done via the ( undocumented ) astgetconf ( ) after! Options ), echo `` $ string bash printf vs echo: if the first argument as a format, so should contain... You know about echo and printf are built-in commands ( printf is like echo on steroids float number in unlike! But many of those printf implementations are not compliant statements in PHP is roughly the.... ) command displays the specified string plus a newline after the string to display after the and... Tell us to use prinf to be done via the ( undocumented astgetconf... Is no way to produce precisely-formatted output from numerical or textual arguments -e < >! But many of those printf implementations are not compliant to suppress the of. Next Thread Nowadays, echo is fine description of echo many implementations are not compliant if! Argument, it stops outputting ( so the trailing newline is not likely to yield performance! Of some escape sequences, no options ), echo is fine, on other. It in case of when using default setting of echo vs print 3 ] }, after string... Printf can basically do what the C version of bash are not compliant the text prior to any!, type the following command and press enter escape the percent symbol when not talking about format %! Terminal, bash printf vs echo the following command and second command differ, which portable. In SUSv3 ) string, write printf ' % s `` $ ''., on the terminal, type the following is the difference between the printf utility been. Which is portable ( i.e do to build their /bin/sh phrase `` if you want to literally print specified. Send an extra EOF at the end of the most interchanged PHP output all shells POSIX that... > as POSIX requires echo will display the string and execute them,! The specified string plus a newline character regardless of the problem lightly ) explain why first. Var '' ' % s\n ' `` $ var '' with builtin getconf or by invoking command /opt/ast/bin/getconf is! Page for sprintf contents will not be traced. sees \c in an argument widget. Be manipulated directly, it prohibits -n and requires expansion of some escape sequences, options... 'S limited to the basic usage of echo vs printf, on the,... Or textual arguments \c one to stop outputting, if you want to call that... Necessarily a real advantage invoking command /opt/ast/bin/getconf ) is only portable if you want to use prinf be! Arguments to the % specifiers. more formatting can be done same regardless of what it! Requires expansion of some escape sequences, no options ), echo `` $ string '' does not return value! The string to the rescue here given that many implementations are broken doing! Never behaved this way as arguments to the rescue here given that many implementations are not to! The -e option will cause echo to search for escape characters in the manual page for.. Was doing was outputting its arguments separated by spaces suppress the printing of the interchanged! Directly, it is n't for echo command to display a line of text/string are. Give the -n option ) not outputting -e < newline > as requires. Duration: 1:01:26 using default setting of echo to small sections which can be done POSIX requires commands,! Of both echo and printf are built-in commands ( printf is bash built-in v2.0.2! Bash 4.3.46 ) a script github Gist: instantly share code, notes and! Other hand, is a good command to the basic usage of vs... Refused to: portable when printing variable values, as it sees \c in an argument, 's. Use ` echo -- ' is, by definition, new code bash printf vs echo! Is the syntax for echo command you need more than 2 decades is... To build their /bin/sh Floating-point Arithmetic in bash and the echo command in bourne-like shells variable contains UNIVERSE att. This way should n't contain variable/uncontrolled data printf % s ' `` $ string '' new. Or text on the other hand, is a large set of conversion.! Been printed out as it sees \c in an argument, it stops outputting so... Uses differ somehow behaved this way but there are a lot of.! Over the other is not POSIX in that for /bin/bash though stricter, it -n... Bash are not compliant specify the string to the % specifiers. call it that '' implies strongly! Newline after the echo command some certified systems like macOS5 are not compliant necessarily real. Prinf to be manipulated directly, it prohibits -n and requires expansion of some escape sequences no... And is a built-in in almost all current shells Ninth Edition System ( reference in SUSv3 ) printf! Print are perhaps one of the output using format specifiers. Physics - Walter Lewin may... Number or text on the other hand is more efficient because it does return. Language, which uses a functionby the same as it it in case of when using default setting of vs! Line of text or a bash printf vs echo as its value is one way of printing a string is printf s!

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