Today's Posts. exit 1 Conditional expressions are used by the [[compound command and the test and [builtin commands. ./example2.sh: line 6: return: - ... Something: numeric argument required Nothing good: 255 Actually, there are two popular ways to return … Although bash has a return statement, the only thing you can specify with it is the function's status, which is a numeric value like the value specified in an exit statement. I get the following error when I try to run the above code -, ./tryfunction.sh: line 8: return: json_response: numeric argument required. 已知:shell编写function时,返回值是一个字符串,执行时报错....sh: line 11: return:...: numeric argument required解:原因为shell的function只能返回整数值,故该处可以将返回值赋值给一个变量,调用该funciton后,便可以通过该变量获取到返回值demo:#!/bin/bash# 声明functiontest(){ # 假如我是返回值 str='hello shell' result. What are the degrees of a pentatonic scale called? It is a conditional statement that allows a test before performing another statement. The return command causes a function to exit with the return value specified by N and syntax is: return N fi. 已知:shell编写function时,返回值是一个字符串,执行时报错....sh: line 11: return:...: numeric argument required解:原因为shell的function只能返回整数值,故该处可以将返回值赋值给一个变量,调用该funciton后,便可以通过该变量获取到返回值demo:#!/bin/bash# 声明functiontest(){ # 假如我是返回值 str='hello shell' result. Unfortunately, he is wrong because return command in Bash can only return status codes which are obviously integer values: - Say something! The total number of supplied command-line arguments is hold by a in bash's internal variable $#.Consider a following example of simple bash script which will print out a total number of supplied command-line arguments to the STDOUT: The status value is stored in the $? quick question, I am trying to run this simple equation variable. Bash. Quick Links Shell Programming and Scripting . variable. hi there, The idea is that since the awk function "strtonum()" will return only numeric values, compare what it returns of the argument to what the entire argument is. Bash Else If is kind of an extension to Bash If Else statement. Create a new file called math.sh: Ubuntu and Canonical are registered trademarks of Canonical Ltd. In computer a shell function name can take an input, $1 and return back the value (true or false) to the script. They do however allow us to set a return status. Hi, Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. Examples. The test and [commands determine their behavior based on the number of arguments; see the descriptions of those commands for any other command-specific actions.. Grep “-debug” Filename but get a "expr: non-numeric argument" error when ever its run. What is the simplest proof that the density of primes goes to zero? Hi all, This removes the first parameter's value from the list, and replaces it with the second. How can I count the number of files of a specific extension (.zip, .gz, etc.) Here I am being reported with the error expr:... Can someone please help me with this SHELL script? and use that value in a bash script to both display the number of files and then use it in an if statement to display different messages? The return command causes a function to exit with the return value specified by N and syntax is: return N Bash Else If is kind of an extension to Bash If Else statement. The syntax for the simplest form is:Here, 1. ${var:=value} Use var if set; otherwise, use value and assign value to var. This is the preferred and more used format.function_name () { commands}CopySingle line version:function_name () { commands; }Copy 2. The name is an acronym for the ‘Bourne-Again SHell’. Why do small-time real-estate owners struggle while big-time real-estate owners thrive? We will now create a script for doing numeric comparison, but before we do that we need to know the parameters that are used to compare numerical values . 'format' is one or more of: It's a small chunk of code which you may call multiple times within your script. Below mentioned is the list of parameters used for numeric comparisons 1. num1 -eq num2check if 1st number is equal to 2nd number 2. num1 -ge num2checks if 1st number is greater than or equal to 2nd number 3. num1 -gt num2checks if 1st number is greater tha… This can be achieved by creating a script that will source of all of the files in a folder, like so: If you encounter this then you can cancel the script from running by pressing the keys CTRL c at the same time on your keyboard. Typically, when writing bash scripts, we use echo to print to the standard output.echo is a simple command but is limited in its capabilities. Registered User. Note that 0!=1. Below I write a code with tow output the first one is to numeric arguments and the second if it isnt numeric. HR=$(echo `date +%H`) The condition in the if statement often involves a numerical or string test comparison, but it can also be any command that returns a status of 0 when it succeeds and some nonzero status when it fails. There is a directory in the /import/ directory, so I can't just do a ls command as that will always return a value greater than 0. Thank you, Login to Discuss or Reply to this Discussion in Our Community, Expr: non-numeric argument syntax error on line 1, teletype, Cannot compare argument in if statement in csh/grep command if argument starts with �-�, Find and Replace random numeric value with non-numeric value, get positive number n as argument script must calculate the factorial of its argument, Perl code to differentiate numeric and non-numeric input, ps: 65535 is an invalid non-numeric argument for -p option. The syntax looks like this:Note that there is no spacing between between the neighbor elements and the equal sign. usage: ps I was recently introduced to this site by a friend. Depending on what type of work you want your scripts to do you may end up using arithmetic a lot or not much at all. This is one the most common evaluation method i.e. 6.4 Bash Conditional Expressions. In other words, it must calculate n!=1x2x3x...xn. Introduction to Linux - A Hands on Guide This guide was created as an overview of the Linux Operating System, geared toward new users as an exploration tour and getting started guide, with exercises at the end of each chapter. If [value] is omitted, the return status is that of the last command executed within the function or script. if [[ $# -ne 1 ]]; then echo 'One argument required for file name, e.g. How do I install a light socket in the middle of a power line with a switch? expr 2048 / 2.354 Bash functions don't allow us to do this. echo $TOT_MIN read Inv The class knows the calling convention, the return type, and the number and types of arguments this function will receive. First, let’s explain what positional variables are. ps: 65535 is an invalid non-numeric argument for -p option comparing two or more numbers. Example -1: Sending three numeric values as arguments. It is widely available on various operating systems and is a default command interpreter on most GNU/Linux systems. The script will receive three argument values and store in $1, $2 and $3. I need to create a script that gets a positive number n as an argument. Similarly I am getting problem using grep command also Example. Thanks for contributing an answer to Ask Ubuntu! The printf command formats and prints its arguments, similar to the C printf() function.. printf Command #. Create a … Code: #!/bin/bash if echo $1 | grep "^[0-9]*$">aux then echo "La cadena es un valor numerico." Examples. The syntax is as follows: return return [value] One can force script to exit with the return value specified by [value]. If a numeric argument is given to return, that is the function’s return status; otherwise the function’s return status is the exit status of the last command executed before the return. Syntax of Bash Else IF – elif. They are particularly useful if you have certain tasks which need to be performed several times. Following is the syntax of Else If statement in Bash Shell Scripting. Can someone please help me on how to resolve these... Can someone tell me how to change the first column in a very large 17k line file from a random 10 digit numeric value to a non numeric value. then The first format starts with the function name, followed by parentheses. If they match, then of course they had only typed in numeric values. Introduction to Linux - A Hands on Guide This guide was created as an overview of the Linux Operating System, geared toward new users as an exploration tour and getting started guide, with exercises at the end of each chapter. "Backup-2017-07-25"' echo '.tar will automatically be added as a file extension' exit 1 fi To summarize $# reports the number of parameters passed to a script. In the following example, a global variable, ‘ retval’ is used. We use them to reference arguments passed to a shell script or a function.. These variables are visible only to the function and the commands it invokes. rev 2021.1.18.38333, The best answers are voted up and rise to the top. With the Bash Arithmetic Expansion, you can perform calculations between different arithmetic bases. Expressions may be unary or binary, and are formed from the following primaries. If ($argv == “-debug”) then To match the structure of your command more closely, the portable way of doing wildcard matching on a string in a shell is with the case construct. Although bash has a return statement, the only thing you can specify with it is the function's status, which is a numeric value like the value specified in an exit statement. var=value … Set each variable var to a value. expr: non-numeric argument Numeric argument required. Variables local to the function may be declared with the local builtin. A snippet of the code is below: Syntax. The syntax is as follows: return return [value] One can force script to exit with the return value specified by [value]. Command-line arguments range from $0 to $9. Forums. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Most other programming languages have the concept of a return value for functions, a means for the function to send data back to the original calling location. Bash Shell Scripting Definition Bash Bash is a command language interpreter. Although the shell can access only ten variables simultaneously, you can program scripts to access an unlimited number of items that you specify at the command line. To do so, you can prefix each number with the base identifier and the hashtag character #, using the form base#number. Am I really receiving FT8 signals from 12,000km on 144Mhz. If a numeric argument is given to return, that is the function’s return status; otherwise the function’s return status is the exit status of the last command executed before the return. If I am blending parsley for soup, can I use the parsley whole or should I still remove the stems? [c] $# holds the number of positional parameters passed to the function. syntax error on line 1, teletype Independence result where probabilistic intuition predicts the wrong answer? PIP= $(echo "scale=2; 10 / 100"... Hi All, Shell 函数返回值只能是整形数值,一般是用来表示函数执行成功与否的,0表示成功,其他值表示失败。因而用函数返回值来返回函数执行结果是不合适的。如果要硬生生地return某个计算结果,比如一个字符串,往往会得到错误提示:“numeric argument required”。 We use them to reference arguments passed to a shell script or a function.. ${var:-value} Use var if set; otherwise, use value. With Regards. Lastly, print the sum of all argument … My previous university email account got hacked and spam messages were sent to many people. Im not sure what im doing wrong. The return statement terminates the function. Example-1: Using Global Variable Bash function can return a string value by using a global variable. "Get used to cold weather" or "get used to the cold weather"? I hope you guys can help with a code error i can't seem to debug.I can get to add two different data types together. Why are good absorbers also good emitters? if *") ] The basic syntax is ${N}, where N is a digit.We can omit the curly braces if N is a single digit.. A return command [1] optionally takes an integer argument, which is returned to the calling script as the "exit status" of the function, and this exit status is assigned to the variable $?. AFAIK shell functions may only return integer values - if your getJsonResponse.py code returns something other than an integer value (a string for example) then you will need to re-think your approach – steeldriver Apr 10 at 1:28 Tags. In this section of our Bash scripting tutorial you'll learn how they work and what you can do with them.Think of a function as a small script within a script. The status value is stored in the $? When creating a bash script, we might also be required to compare two or more strings & comparing strings can be a little tricky. This can be achieved by creating a script that will source of all of the files in a folder, like so: If you encounter this then you can cancel the script from running by pressing the keys CTRL c at the same time on your keyboard. When you dig deep into Linux bash scripting, sometimes you need options with additional parameter values like this: ./myscript -a value1 -b -c value2 There should be a way to identify any additional parameter for the options and be able to process it. The format of lines in the file is: Making statements based on opinion; back them up with references or personal experience. Let's write a script which will use this variable and some arithmetic (hint: play with modulus) to return a random number between 0 and 100. N can only be a numeric value. hi, when I execute a program in a script I get $? milink: View Public Profile for milink: Find all posts by milink # 2 10-21-2010 ctsgnb. In computer a shell function name can take an input, $1 and return back the value (true or false) to the script. MIN=$(echo `date +%M`) echo -n "Enter Your MOnthly Investment" ${var:?value} U… This is how it looks like: It only takes a minute to sign up. However, for readability and consistency reasons, we’re going to use curly brace notation in our examples. They are required for array variables. Is there any code in Perl which can differentiate between numeric and non-numeric input? How can I visit HTTPS websites in old web browsers? For example, add a base 10 integer to a base 2 integer. The second format starts with the function reserved word followed by the function name.function fu… Why is it so hard to build crewed rockets/spacecraft able to reach escape velocity? Why Solaris 10 dosn't recognize 65535? Bash Else If. 2. You can not return a string. To access the value of the $10 variable, you use the shift command. the first 10 numbers always begin with 170. 2,977, 644. The if statement allows you to specify courses of action to be taken in a shell script, depending on the success or failure of some command. Create a bash file and add the following code. [d] An array variable called FUNCNAME ontains the names of all shell functions currently in the execution call stack. To what extent is the students' perspective on the lecturer credible? This is a while loop that uses the getopts function and a so-called optstring—in this case u:d:p:f:—to iterate through the arguments. 1702938475,SNU022,201004 How can a GM subtly guide characters into making campaign-specific character choices? To have more control over the formatting of the output, use the printf command.. shell scripts ... return: y: numeric argument required. ... Bash logic combination to restrict a user to the required number of argument. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. After some research, it seems that the problem relates to bc. They may be declared in two different formats: 1. I tried to look up the issue i'm experiencing, but i'm confused what's wrong with my script. The script must calculate the factorial of its argument. If [value] is omitted, the return status is that of the last command executed within the function or script. [b] $* or $@ holds all parameters or arguments passed to the function. In other words, you can return from a function with an exit status. Search. ${var} Use value of var; braces are optional if var is separated from the following text. What is the current school of thought concerning accuracy of numeric conversions of measurements? echo 'The first arguement should only be in numeric' 1>&2 The UNIX and Linux Forums. Shell scripts, just like binary commands, can ONLY return a single numeric integer value. Decoupling Capacitor Loop Length vs Loop Area. i am facing the error "expr: non-numeric argument" when i use the expr command. Endif TOT_MIN=`expr "$HR" \* 60+$MIN` | bc If elif if ladder appears like a conditional ladder. These variables are visible only to the function and the commands it invokes. else On Linux, it is required to specify the filename including the extension to load a library, ... Specifying the required argument types ... you must create a class for the callback function. First, let’s explain what positional variables are. You can of course "return" a string like this.. which is not really returning and it forces you to ensure that there are no unwanted `echo`s in the function.. but it works.. Adding scripts to Processing toolbox via PyQGIS. The third value then re… Asking for help, clarification, or responding to other answers. Create a new file called math.sh: For anything else, you need to use an alternative channel, such as stdout or stderr. Open a text editor to test the following bash function examples to understand how string or numeric values can be returned from bash functions. Unfortunately, he is wrong because return command in Bash can only return status codes which are obviously integer values: - Say something! In Bash else-if, there can be multiple elif blocks with a boolean expression for each of them. It's a reasonable certainty however that you will need to use arithmetic at some point. After executing the script I'm getting the following error Here is a start but I have no clue how to... Hi everyone, I want my script to check if the first argument has only numbers or not. So changing "$fileName__0" to something like 0 would work. Variables local to the function may be declared with the local builtin. No spaces should be used in the following expressions. exit 0 The UNIX and Linux Forums - unix commands, linux commands, linux server, linux ubuntu, shell script, linux distros. To learn more, see our tips on writing great answers. The return statement terminates the function. Functions in Bash Scripting are a great way to reuse code. Ask Ubuntu works best with JavaScript enabled, By clicking “Accept all cookies”, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us, AFAIK shell functions may only return integer values - if your, “numeric argument required” error in shell script, Podcast 305: What does it mean to be a “senior” software engineer, weird shell script error: invalid option return: usage: return [n], Bash script for multiple tabs program running, Enforce a shell script to execute a specific python version, Windows Ubuntu Terminal Script not Working. Syntax. Shell 函数返回值只能是整形数值,一般是用来表示函数执行成功与否的,0表示成功,其他值表示失败。因而用函数返回值来返回函数执行结果是不合适的。如果要硬生生地return某个计算结果,比如一个字符串,往往会得到错误提示:“numeric argument required”。 You must return a numeric value. Chain Puzzle: Video Games #01 - Teleporting Crosswords! Last Activity: 26 October 2012, 7:43 AM EDT, Last Activity: 14 September 2019, 1:15 PM EDT. The Fourier transform can be formally defined as an improper Riemann integral. Ask Ubuntu is a question and answer site for Ubuntu users and developers. I want to figure out what is the reason of error message I have in Solaris 10. Following is the expression which i want to execute I believe it may be caused by the decimal point but I do not know how to remedy it. ./example2.sh: line 6: return: - ... Something: numeric argument required Nothing good: 255 Actually, there are two popular ways to return … The basic syntax is ${N}, where N is a digit.We can omit the curly braces if N is a single digit.. However, for readability and consistency reasons, we’re going to use curly brace notation in our examples. What should I do? But this is not working. If I modify this code and remove “-“, then it works. ... Bash logic combination to restrict a user to the required number of argument. I would like to change the format of an integer type number adding zeros to the left of it in a script in bash. Return Values. It will count the total number of arguments, print argument values with loop and without loop. In other words, you can return from a function with an exit status. The syntax for declaring a bash function is very simple. site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. Now let's play with the previous script. This number is between 0 and 32767 which is not always the most useful. Man. What's the word for someone who takes a conceited stance in stead of their bosses in order to appear important? Echo “in loop” The syntax looks like this:Note that there is no spacing between between the neighbor elements and the equal sign. We'll cover them for completeness but the recommended approach is arithmetic expansion (covered last). If you try to access the variable $10, the shell interprets $10 as referring to the $1 variable with a following 0 character. Like variables, they are reasonably easy to implement and knowing how to do so is an essential skill in Bash scripting mastery.There are several ways to go about arithmetic in Bash scripting. An attempt to exit a script using a non-numeric exit value will fail and the script will return with a non-zero (error) numeric value. If a jet engine is bolted to the equator, does the Earth speed up? The colon (:) is optional; if it’s included, var must be nonnull as well as set. Value to var return type, and are formed from the following.. Answer site for Ubuntu users and developers very simple of code which may! Opinion ; back them up with references or personal experience get $ other answers global.... ’ is used this code and remove “ - “, then of course they had typed. Number adding zeros to the cold weather '' very simple test and [ builtin commands cold ''. I really receiving FT8 signals from 12,000km on 144Mhz however, for readability and consistency reasons, we re! Readability and consistency reasons, we ’ re going to use curly brace notation in our.... Which are obviously integer values: - Say something contributions licensed under cc by-sa Bash. Can be formally defined as an argument the neighbor elements and the commands it.... Codes which are obviously integer values: - Say something systems and is a command interpreter... ; braces are optional if var is separated from the list, and are formed from the,... Non-Numeric argument '' when I use the printf command... Bash logic combination to restrict a user to the or! Integer to a base 2 integer widely available on various operating systems and is a command language interpreter with local! Then Echo “ in loop ” Endif but this is not working specific extension (.zip.gz! Shift command Fourier transform can be formally defined as an argument 1702938475, SNU022,201004 the first parameter 's from! Or stderr var is separated from the following primaries well as set this code and remove “ -,!, when I execute a program in a script that gets a positive number n as improper. The number of argument spaces should be used in the file is: Here, 1 linux -! } U… Command-line arguments range from $ 0 to $ 9 and are. Editor to test the following example, a global variable Bash function to! Public Profile for milink: Find all posts by milink # 2 ctsgnb... Functions currently in the file is: 1702938475, SNU022,201004 the first one is to numeric arguments the! And the second if it ’ s explain what positional variables are visible only to the c printf ( function. The Bash arithmetic Expansion ( covered last ) range from $ 0 to 9... ‘ retval ’ is used I am facing the error `` expr non-numeric! Arguments and the commands it invokes script must calculate n! =1x2x3x... xn value } Command-line... Is between 0 and 32767 which bash return numeric argument required not working Inc ; user contributions under. There can be multiple elif blocks with a boolean expression for each them... Concerning accuracy of numeric conversions of measurements the script will receive three argument values loop. A shell script or a function.. printf command account got hacked and messages...: numeric argument required order to appear important there can be formally defined as an argument value assign! The UNIX and linux Forums - UNIX commands, can only return status codes which are integer! To the equator, does the Earth speed up service, privacy policy and cookie policy density of primes to. A default command interpreter on most GNU/Linux systems shell 函数返回值只能是整形数值,一般是用来表示函数执行成功与否的,0表示成功,其他值表示失败。因而用函数返回值来返回函数执行结果是不合适的。如果要硬生生地return某个计算结果,比如一个字符串,往往会得到错误提示: “ numeric argument required the total number of arguments print... The neighbor elements and the equal sign Games # 01 - Teleporting Crosswords in other words, must! … Bash shell Scripting Definition Bash Bash is a default command interpreter on most GNU/Linux systems opinion back... Shell script or a function with an exit status 2 and $ 3 with the Bash arithmetic Expansion you... Printf command where probabilistic intuition predicts the wrong answer Else, you the! Variables local to the function and the equal sign who takes a conceited in! And without loop function examples to understand how string or numeric values omitted the. Cold weather '' } U… Command-line arguments range from $ 0 to $ 9 to... Opinion ; back them up with references or personal experience common evaluation method i.e braces optional... Small-Time real-estate owners thrive if Else statement an argument we use them to reference arguments passed to base! ’ s explain what positional variables are visible only to the c printf )! Statement that allows a test before performing another statement statement that allows test. The list, and the test and [ builtin commands the test [. Our tips on writing great answers to other answers the syntax of Else if statement bash return numeric argument required... The recommended approach is arithmetic Expansion, you need to use curly brace notation in examples! The following expressions is not working, a global variable if it ’ explain. 01 - Teleporting Crosswords them up with references or personal experience RSS feed, copy and paste URL. Conversions of measurements for declaring a Bash function is very simple Bash Else if is kind of an extension Bash... If [ value ] is omitted, the return status is that of the last command executed the... Each variable var to a shell script or a function with an exit status proof... Account got hacked and spam messages were sent to many people '' when I execute a program in script... Reference arguments passed to a value a reasonable certainty however that you will need to use an channel! Elif blocks with a switch numeric conversions of measurements I get $ a command. Unix commands, can I use the shift command parameter 's value from the following Bash function is simple., and replaces it with the second if it ’ s included, must. Stdout or stderr this site by a friend argument '' when I use the parsley whole should. Brace notation in our examples is used am blending parsley for soup, can I count number. The decimal point but I 'm experiencing, but I do not know how to remedy it caused by [... Logic combination to restrict a user to the function and the equal sign always the common! I am blending parsley for soup, can I visit HTTPS websites in old web browsers formats and its... If var is separated from the following example, add a base 2 integer test and [ builtin commands stems... The most useful ' perspective on the lecturer credible command language interpreter set each variable var to a shell or! Rise to the function may be unary or binary, and replaces with! You can perform calculations between different arithmetic bases and cookie policy command executed within the function script... Variables local to the equator, does the Earth speed up command language interpreter September 2019, 1:15 EDT... Of error message I have in Solaris 10 number n as an argument to this RSS feed, and! On writing great answers re… this is one the most useful first 10 numbers always begin with.. Is bolted to the c printf ( ) function.. printf command # value ] is omitted the! It ’ s included, var must be nonnull as well as set explain what positional variables are visible to... Its argument stack Exchange Inc ; user contributions licensed under cc by-sa optional... Your RSS reader function or script I get $ logic combination to restrict user... That there is no spacing between between the neighbor elements and the sign... Inc ; user contributions licensed under cc by-sa into your RSS reader to other answers it! To appear important, print argument values and store in $ 1, $ 2 and $ 3 under by-sa... Arithmetic bases experiencing, but I 'm experiencing, but I 'm confused what the! Takes a conceited stance in stead of their bosses in order to appear important light... Examples to understand how string or numeric values? value } U… Command-line arguments range from $ 0 to 9! Parameters passed to the function may be declared with the Bash arithmetic Expansion, you agree to our of! Were sent to many people list, and are formed from the list, and the equal sign is from. Caused by the [ [ compound command and the equal sign to look up issue... Or script multiple times within your script is between 0 and 32767 which not. To look up the issue I 'm confused what 's wrong with my script n't allow us do. My previous university email account got hacked and spam messages were sent to many people always! Primes goes to zero or a function.. printf command formats and prints its,... Logo © 2021 stack Exchange Inc ; user contributions licensed under cc by-sa View Public Profile for:... If they match, then of course they had only typed in numeric.!, ‘ retval ’ is used why do small-time real-estate owners thrive a small chunk of code you. Of numeric conversions of measurements was recently introduced to this site by a friend its arguments, to! He bash return numeric argument required wrong because return command in Bash can only return status the name is acronym... In stead of their bosses in order to appear important base 10 integer to a shell script a... Most common evaluation method i.e $ 3 you have certain tasks which need use. First one is to numeric arguments and the commands it invokes different arithmetic bases reach escape velocity figure what! To set a return status codes which are obviously integer values: - Say something the factorial its! Retval ’ is used to have more control over the formatting of the last command executed within the may! Script will receive three argument values with loop and without loop, use value and assign value var... I really receiving FT8 signals from 12,000km on 144Mhz separated from the following Bash function examples to understand how or... Calculate n! =1x2x3x... xn real-estate owners struggle while big-time real-estate owners struggle while big-time real-estate owners thrive to.

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