Shell script variable in double quotes. Set automatically upon receipt of a SIGWINCH signal.

Shell script variable in double quotes My problem is that every variable get "double quots". echo login $a is $d. sh 'te'st' There's a syn Skip to main content. SET myVariable= " \\"myValue \\" " I want to add a variable ${date} in the following bash script: ffmpeg -i in. Must be easy, but I am new to shell scripting, so I couldn't figure it out. In Bash (which follows the POSIX shell standard), single quotes preserve every character literally, which means there is no way to escape contents within single quotes. To pass the value quoted, and with quotes in the value itself, Linux Shell Scripting is a powerful tool, but mastering its nuances is key to writing effective scripts. Scenario 2: Using Variables Within JSON Strings. Trim(). txt" | grep "text") Then use that variable in another command: I'm learning shell scripting for an exam and in our teachers book at one place he writes in an example the following: # This script expects a folder path as an argument. g. Modified 10 years, 4 months ago. The first option is the right way. For example: The last 2 solutions (putting double quotes inside the arg) wont work properly as the shell is just going to pass literal quotes to . With the double quotes around the variable, the internal spacing is preserved and the expansion is treated as one argument to the printf command. answered Feb 23, 2016 at 19:41. This will work for all characters except single quote itself - i. This solution works in any Bourne/POSIX shell. Viewed 83k times 16 . /myscript. \nShe's fine, though, don't worry. Here, we are telling awk to replace s which is equal to single quotes. You'll often use quotes in Linux command line. 18. export MY_HOME="/home/my_user" More details you can skip on first reading. This ignorance is similar to the other common mistake of not using double quotes to prevent inadvertent word splitting or globbing. All of those get run together into a single word in the Addendum: Supporting Non-Bash Remote Shells. ttf:text='Today is ${date}':fontsize=6" out. so i have multible double and single qoutes and multible variables in the html part but i cant find out how to escape all that stuff right that the script runs as expected AND fill in the variables in the html code. Therefore, beside the question that this was marked duplicate of, I would also point to Difference between single and double quotes in Bash. To illustrate another difference: $ bash script "long space" No There's a trick you can use anytime you need to have the shell accept as a single argument something that has both single quotes and double quotes. Example 2: Passing Arguments Using Double Quotes in Bash. But, we also wrapped the variable in double quotes, as mentioned above this is best practice and will be required in some scripts you write. I see two potential problems with how you're reading and using the password: When you use the read command without the -r option, it'll try to interpret escape (backslash) sequences, which may cause trouble. 6k 22 22 gold badges 109 109 silver badges 133 133 bronze badges. In my script I execute an rdesktop command that should have -u '' (<- 2 single quotes) as a parameter. If switching to double quotes would require excessive escaping of other metacharacters, note that you can mix and match quotes in the same shell word: Getting JSON value from JSON String using Shell Script. nl=$'\n' svn ci -m"Added new file: ${oFileName}${nl}Orig loc: ${oFileFull}" "${oFileName}" The reason you have to escape it "twice" is because you're entering this command in an environment (such as a shell script) that interprets the double-quoted string once. cd does not work with a variabe that has a variable which has a path. alias foo=\$(command)), it too will execute each In the above image, I have escaped single quotes enclosed in double quotes including the variable expansion. This best practice prevents word splitting and globbing issues, resulting in more reliable and maintainable I am trying to run a command in shell script which demands its argument to be passed in below format which includes double quotes with string. bash how to quote string with quotes. Windl. Skip to main content. We’ll explore a critical aspect often overlooked: the subtle yet significant differences between using double quotes versus single quotes, or no quotes at all, when handling arguments, especially in Linux Shell Scripting. vim You can detect how many positional parameters were passed to your script by examining the $# parameter. So for example: VARIABLE=$(cat "file. So all four are OK. It’s necessary to escape double quotes when you want to include these as literal characters within a single quoted Difference Between Single and Double Quote in Bash Shell Quotes are an integral part of shell scripting and Linux command but they could often be confusing for new users. Local variables or params will yield a bad substitution. It's ugly A simple example of escaping quotes in the shell: $ echo 'abc'\''abc' abc'abc $ echo "abc"\""abc" abc"abc It's done by finishing an already-opened one ('), placing the escaped one (\'), and then opening another one ('). Note that this is a special form and is only recognized as such if it appears exactly this way. If you want to pass quotes, escape them with a backslash: # . The characters have special meaning when used with double quotes, and before display, they are evaluated. Just for the record, I had a problem particularly with a list-based command passed to Popen that would not preserve proper double quotes around a glob pattern (i. sh. I am using bash shell. im using PS 7. Ask Question Asked 9 years, 3 months ago. To pass the value quoted, use "$1". Unfortunately, it is also a very confusing topic and, when used incorrectly, a big source of bugs and weird behavior in scripts. 1 of the POSIX shell syntax specification:. (There are slight differences between the shells on this. 19 (latest stable release at time of writing). After reading other posts I tried putting the command in an array, but I Similar to variable interpolation, command substitution works only when we do it inside double quotes or omit the quotes. bash variable with double-quotes . 1. So that it would handle the filepaths which has spaces but without double quotes, it won't handle the filenames which has spaces in it. 4,681 1 1 gold badge 18 18 silver badges 17 17 bronze badges. This makes it possible to escape ', ", and ` inside of quotation marks. To pass the literal " through to the actual bash shell Let's say I have a script which echoes $1 #!/bin/bash echo $1 It's called test. Double quotes are more flexible than single quotes. In Bash, you can easily pass arguments or How do I pass my $1 along with double quotes inside the script? linux; bash; shell; Share. 1 which covers quoting variables. You can close the quotes before the variable and then open again just like concatenation but it’s not great for multiple variables. bashrc then command will be executed when the alias command itself is run during . I have made the "today's date" variable without problem: So I want to include in a shell script a sqlplus command, the problem is that one of the parameters could be a double quote char (") but sqlplus thinks is the start of a string. Then I call /bin/test. I want to keep the double quotes of the original string。 The json string is dynamically generated, the data content is undefined, I can't use sed to add double quotes # The json_str is externally Note that you need double quotes for the sed expression, in order to use the shell variable, see this answer to Shell variables in sed script. Set automatically upon receipt of a SIGWINCH signal. It is an ordinary bash parameter that is set by bash itself. Once single quote is found replace it with double quote. That would be very bad if their syntax highlighting encouraged bad coding practice. The real problem here is your app interpreting quotes in an arg. . Commented Nov 18, 2022 at 9:26 @U. /configure. Improve this question. Prevent bash from adding single quotes to variable output. Your problem has nothing to do with Popen as such. pre-dictionaries-common $ echo $(ls Conversely, a shell variable that is defined in a shell script will become an environment variable if you export it. AdminBee as C. Because the shell won't let you escape quotes, you need to turn it into multiple abutting quoted strings, switching between single and double quotes as needed to protect what's inside. Parsing variables in curl with bash script. – Hemanth Annavarapu. There are used when you need to read something from standard input, but you don't want to create a file to provide that input. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for Follow the script below to remove double quotes from a string in Bash: {print $2} tells to print the second field that is the content between the double quotes inside the string2 variable. Without quotes it would be broken up into multiple parameters, depending on the value of IFS which contains space, TAB and newline by default. Since Bash treats single and double quotes differently, I have a command I need to run in a bash script that takes the output of a previous command and inserts it into a new command. You could also avoid the double-quotes, and thus avoid the first interpretation: $ /bin/sh -c 'ls 1\`' 1` When you use any script or string in shell, simply always enclose it in single quotes: sed 'script' file var='string' unless you NEED to use double quotes to let a variable expand and then use double quotes unless you NEED to use no quotes to let globbing and file name expansion happen. Using double quotes is Based on the comments above by awk experts and some research, I am posting this answer: awk strings are enclosed in double quotes, not single quotes; more precisely: single quotes are not string delimiters in awk, unlike shell awk attaches no special meaning to single quotes and they need to be enclosed in double quotes if used in string literals I would like to store a command to use at a later time in a variable (not the output of the command, but the command itself). Commented Feb 1, 2017 at 14:46. Substituting INTO double quotes? 3. Double Quotes: To expand the variable value inside a string we use the double-quotes. command "string" This string is stored in variable var1. And a single quote to start the next single quoted string. case statements and assignments are the only places I intuitively accept that the variable is not subject to field splitting, but even in those cases I would double quote the expression. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company You can nest double quotes within double quotes by escaping them though. e. The one exception is I don't quote the value when doing a variable assignment (unless required, such as when the value contains a Nothing inside single quotes will be expanded by bash, including any double-quotes, and variable names. The final quoted string is just ve. bash: quote var with quotes. Your script, corrected: Difference between double quote and single quote; Double quotes for variable and command substitution; Newlines and control characters; Quoting literal text; Read a file (data stream, variable) line-by-line (and/or field-by-field)? Redirection; Scoping; Script shebang; Scripting with Parameters; Select keyword; Sleep utility; Sourcing I write a bash script and get some user input with read. You can use this as another way to have dynamic variables inside a shell script. Then you want to have an embedded double quote character, so you use two of them. But if you escape the $ with the $() form (e. The reason why shell variables don't automatically become environment variables is partly that a script might accidentally use a variable name that's meaningful to a program that it launches, and I've created a bash script that takes a parameter. Another way to escape double quotes easily in Bash is to use the ANSI-C quoted string $’’. Commented Feb 1, 2017 at 14:51. Trim('"') The first removes all whitespace characters from both sides of the string (not just spaces, but also tabs, newlines etc. How to use echo to wrap a variable with quotes. Bash script echoes variable name instead of value. It does not work with double-quotes either, nor with $*. Stack Overflow. 0 The main difference is that the quoted version is not subject to field splitting by the shell. It means that Bash will substitute the value of any variable within the string and execute any command enclosed in a $() or `` symbol. Finding edge cases in the language to avoid double quoting is folly. Use perl or python instead - they both have good libraries with AWS & S3 support. Poor whiskers takes a tumble. sh" e Skip to main content. In POSIX shells, quoting is one of the most important mechanisms. If the directory name does How to keep double quotes in variables in shell. bashrc interpretation. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for In shell, "quoting is used to remove the special meaning of certain characters or words to the shell" (bash manual). – codeforester. It isn't enough to say that whatever unknown code you tried doesn't work. Escape a single @Moi - automation is not a big deal, though you will have to sanitize the variable of " characters - only the first and last should be sufficient. The following implements that logic, and passes "" to the called program (in this case echo) if the parameter As you can notice that the login_token value is embedded with double quotes when passed as a variable and this causes the failure. How to properly construct a bash command argument? 1. Always wrap strings and scripts in single quotes unless you need to use double quotes (e. Quoting is hard, but I feel that you’re making it harder than you need to. In echo its printing correctly but for the command we are getting as "Unterminated quoted value" Please see the script and argument passing method: [root@geopc]/root# . sql " /home/myuser/Desktop/ I already enclosed them in: single quote, double single quote, double quote, double double quote. – The reason to use double quotes instead of single quotes is to allow variable interpolation. ), followed by the second one to remove the Double quotes escape most characters, except the double quote " the backtick `, the dollar sign $, the backslash \, and the exclamation mark !. bash - then you have to use ==. In the shell, it looks like this: run_script -x '*082512*' And that works fine. Learning the language well enough to understand those edge cases might be useful, but expecting others shell-script; variable-substitution; Share. In truth, this is not actually a problem, the problem is that you didn't know it or why bash behaves like this - "it's a feature, not a bug". This is the command: sqlplus username/ @file. To execute, use bash filename. Peter Mortensen. How On line 12 of our script, we echoed the variable inside of double quotes. Then you also need to escape the double quotes that you are searching for, using \". We are trying to pass an argument with single and double quotes to a shell script and executing with this argument. raju raju. Nov 7, 2023 — Abhishek Prakash. You should also always quote any variable that contains a filename. Commented Apr 16, 2020 at 1:04. Stack Exchange Network. jar HERE I NEED TO PUT -&g If you did touch 'foo ' 'bar ' baz, your example in the comment above would show the globbing -- there's no whitespace in IFS, so the space before the first double-quote is being treated as literal, hence the glob finds no matches when the only items to be matched are foo, bar and baz (with no spaces in the names). You begin the string with a single double-quote, indicating the start of a string literal. Double quotes (") in Bash allow passing strings with spaces as a single token: echo "string with spaces" # Valid. Using double quotes we From the image, you can see that whenever I have used the history expansion operator with a history reference number enclosed in double quotes, Bash recalls and executes the specific command according to the given reference from the command history. sh asd \"asd\" \'asd\' Share. With "indirection", bash allows a shell variable to reference another shell variable, with the final value coming from the referenced The escape characters are not needed for a single quote within double quotes. Follow edited Jun 14, 2014 at 13:13. 3. Just use: $ cat script #!/bin/sh echo No quotes $1 echo "Double quotes $1" Now, let's run it: $ bash script "foo*" No quotes foo111. The following to lines are identical to bash: 'foo bar' foo' 'bar There is no need to quote the alphabetic characters - but it enhances the readability. Finally, the script displays all the results using the echo command. cd $1 if [ $? -ne 0 ]; then echo "Folder not found"; exit 1; fi To use a single quote inside a single-quoted string (in which no interpolations (expansions) are performed by design), you must use a workaround: $ echo 'I am 6'\'' tall. py -c ". This is called "indirection". With double quotes the outcome of the command expansion would be fed as one parameter to the source command. script 2. Viewed 6k times 3 . Bash pass variable as argument with quotes . Ask Question Asked 10 years, 4 months ago. Using ($’’) Syntax to Escape Double Quotes in Bash. Expand variable inside curly braces, inside single quotes, inside double quotes Hot Network Questions The use of past perfect with time expressions All examples are of variable assignment from command substitution, so they are equivalent. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Shell Script to remove double quotes within the column value. echo variable result in quotes BASH. sh 'localhost:9199/jmxrmi -O So, single quotes are not great if you wanted to use the variable expansion and other related stuff. Tried preprocessing quotes and double quoting. In your case, only special characters like " and < must be quoted. For example, if this is 2 or greater, then you know that something was passed for $2, even if $2 is empty (quotes removed by calling shell). I use jq to process json str, but the shell does not retain double quotes. ' I am 6' tall. I have to format body of a json that gets some values substituted from user environment variables. When working with JSON strings, you often need to include variables within the JSON structure. Long answer: Putting commands (or parts of commands) into variables and then getting them back out intact is complicated. repo forall -c '. This is not a matter of preference or options, or something that can be worked around somehow - it's how single-quotes work, and ** EDIT **: I have to use the double quotes around the string because my script for some reason can't read the string is its looks like this: '-arg "hello world"' shell environment-variables Using "$@" will substitute the arguments as a list, without resplitting them on whitespace (they were split once when the shell script was invoked), which is generally exactly what you want if you just want to repass the arguments to another program. shell - wrapping variables in quotes. I've tried to add quotes in the assignment statement itself. The string passed as the second command line argument to sed has double quotes around it, and the variable is within those quotes and will be expanded by the shell. How do I expand a variable inside single quotes? 1. I need to wrap a substitute variable in double quotes in shell. /abc. This is where the escaping starts: you escape the double quote character with another double quote character. Each variable assignment shall be expanded for tilde expansion, parameter expansion, command substitution, arithmetic expansion, and quote removal prior to assigning the value. , %~1 to remove enclosing double-quotes from the 1st parameter) and, sadly, there is no direct way that I know of to get echo to print a variable value faithfully without the enclosing double-quotes. This is the solution. This is likely the closest you will get without getting messy. As per Gilles's answer, quoting isn't necessary on right hand of assignment to variable, since word splitting doesn't occur there. , via a #!/bin/sh shebang line) will likely misbehave if they are actually run by the "real" /bin/sh – this is of special interest when, say, producing init scripts, or packaging pre- and post-scripts, and can land one in a surprising place during installation of a In a POSIX shell, assuming in your string there is no variable, command or history expansion, and there is no newline, follow these basic prescriptions: To quote a generic string with single quotes, perform the following actions: Substitute any sequence of non-single-quote characters with the same sequence with added leading and trailing single quotes: 'aaa' ==> ''aaa'' Escape with a It doesn't do a “double substitution” because there's no such feature in any of the common shells (not with this syntax anyway). True, that. In a Windows XP . asked Jun 14, 2014 at 12:55. sh myuser But Jenkins is wrapping the whole sudo line in single quotes which results in my log files not been deleted (although the Jenkins job passes successfully): If you want the expression to expand, use double quotes instead. 1 is to print the line. ; That second point usually means that your COLUMNS variable will only be set in your interactive shell, not in a bash script. Dealing with From the image, you can see that I have directly escaped the double quotes that are enclosed within a single-quoted string without using any characters. 2 "Ignore" quotes in positional I've a variable, wich contains all types of characters myvar="alfanum;001String" and I need to pass them to a command with a single quotes in this way java -jar myapp. When a string has neither variables nor whitespace, there is no reason (other than style) to use any quotes at all. When you use a variable in a shell command or script without quotation marks, the The main difference lies in which scripting language you are using. txt foo11. Avinash Raj Avinash Raj. For example string="single quote: ' double quote: "'"'" end of string". Are you not allowed to use variables in these statements? Or more likely, is some special syntax required? I can't single quote obviously, and I tried double quoting. But once I try to run it in a script with a variable for the date, I can not produce those single quotes. ' set sentence2 = "The man said \"hello\"" It's checked into cvs in a shell folder, Jenkins is configured to execute it on a Linux machine via a job with 'Execute Shell' build step: bash -ex shell/clear-logs. This works because quoted strings next to each other are considered a single string and you can switch 1. This will be an easy one, but in my memories, when shell scripting, using double quotes would allow expanding globbing and variables. Aknesil points out, is that bash does not remove double-quotes after expanding a variable. Using double quotes prevents the splitting, while letting the variable expansion take place (unlike single quotes). Trying to find a way via shopt or something so the json string is substituted correctly in bash script but preserves/puts back the double quotes to be a valid json. You should put shell variables inside quotation marks to ensure that they are interpreted correctly by the shell. select-wordlist words words. Either use single quotes 'around the "whole pattern"' to automatically escape the doubles or explicitly "escape the \"double quotes\"". Follow edited Sep 16, 2021 at 13:56. 2. It's not what I want, but anyway there are no other solutions (spent whole night The second line without double quotes (echo 1&echo&echo) shows what happens when the double quotes are actually missing in the script execution (and you get 3 commands on the Jenkins console): + echo + echo 1 1 + echo One reason for not using double quotes around variables in shell scripts is that in most editors syntax highlighting no longer emphasizes variable names then ;-) – U. The double quote is missing at the end because after the "V" there is a carriage return that moves the "cursor" back to the beginning of the line. "Today is ${date}. It will also treat the backslashes as interpretable characters. Difference Between Single and Double Quote in Bash Shell. About; Products OverflowAI; Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; This tutorial is written to help people understand some of the basics of shell script programming (aka shell scripting), and hopefully to introduce some of the possibilities of simple but powerful programming available under the Bourne shell. – chepner. But this doesn't work: /bin/test. command "string" This string Double Quotes: To expand the variable value inside a string we use the double-quotes. The above image illustrates the deletion of double You can enclose the double quotes in single quotes: echo '"'hola'"' Or alternatively the whole text, including the double quotes: echo '"hola"' Share. So, let's break down what set -x is showing you: Variables are expanded in double quoted strings, but not in single quoted strings: Variables in shell command in shell script not resolving. 2 (Busybox, actually). String-splitting and globbing (the steps which double quotes suppress) are not in this list, and the others aren't relevant The last one is complicated - there are two single-quoted strings run together with some unquoted text. The Maybe also point out that switching from single to double quotes requires any $ or ` in the sed script to be escaped with a backslash, to protect it from the shell's substitution mechanism for double-quoted strings. Let’s try out some commands to see how this works: $ echo "$(ls /usr/share/dict)" american-english british-english README. In Bash, you could use the following one-liner: [[ "${var}" == \"*\" || "${var}" == \'*\' ]] && var="${var:1:-1}" This will remove surrounding quotes (both single and double) from the string stored in var while keeping quote characters inside the string intact. Double quotes already escape single quotes. Double quoting is not always needed, but it's easier to remember to always double quote than to memorize the contexts in which you don't need to. Example: tcsh has a newer variable backslash_quote. My Bash version is 3. This article will demystify quotes for you. If you have alias foo=$(command) in your . " Bonus: Doing this way you won't have to escape your single quotes. If they were standalone, i. I have a simple script as follows: command=&quot;ls&quot;; echo &quot;C I'm having trouble using a single quote in a command executed from within a shell script. Try: bash variable string with quotes and double quotes. I'm extremely confused with this, I miss Python! NOTE: The following applies to bash, ksh, and zsh, but NOT to (mostly) strictly POSIX compliant shells such as dash; thus, when you target /bin/sh, you MUST double-quote the RHS of export. All was OK until I did not have to use double quotes for single parameter, but words separated by space. One caveat: printf %q is guaranteed to quote things in such a way that bash (or ksh, if you're using printf %q in ksh locally) will evaluate them to exactly match the input. py -p '"'a!s!d!f'"' -c 'ifconfig'" I am running a shell script within the Jenkins pipeline and i want to print into a text file latest files names column created by date, i dont want want to print time & date column etc, just . Share. bat file, how do I set a variable value to use double quote? I couldn't find special characters for batch file. Here, the result is stored in the updated_string2 variable. The output is test. When the shell expands a variable on the command line, if the variable was in double-quotes it's not parsed; if it was not in quotes, spaces in it are parsed as argument Double quotes prevent word splitting and forces Bash to interpret the enclosed characters as a single string value. The good news is you can end your single-quoted section and immediately start a double-quoted section to introduce the variable, and it will all be concatenated into a single argument for the application (curl). Suppose, if I pass the value of login_token directly in the curl command, then the authentication is successful. I tried below methods but, not able to achieve the requirement. What you want are single quotes on the outside and single quotes in the inside. what was suggested in the Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company In older shells, including ksh88 and pdksh, your only recourse when you have a variable containing another variable name and want to use the value of this variable eval, as explained by Bruce Ediger. quotes in bash argument fail with curl. If you wanted to set nodeNumm to the output of the command, correct syntax would be: nodeNumm=$(bash -c "${nodeSayi} | grep -c '\"\"'") There is however no point in running the grep in the subshell, which can get us rid of the outer quotes Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Visit the blog Because syntactic quotes aren't part of the command that's actually run; they're removed by the shell after it uses them to determine how to interpret a command line character-by-character. – In particular, the plain Bourne shell won't know what to do with $(), so scripts which claim to be compatible with it (e. 7. The best you can do with single quotes is to use '\'' wherever you need an embedded single quote. Without the double quotes, pathname expansion is performed. Windl you should report that as a bug to the maintainers of the editor you use. In zsh, ${${FOO}} is valid and is a double substitution, but it behaves differently from what you'd like: it performs two successive transformations on the value of FOO , both of which are the identity transformation, so it's just a fancy way of writing ${FOO} . Your choices are: Concatenate differently-quoted strings by placing them next to each other:. Is In the second case, $@ is expanded out to rsync -avz -e ssh -c blowfish source user@remote:dest/, missing the single quotes. To achieve this, we wrap the double quotes inside of single quotes (so that they are interpreted literally). 4. The first one contains I\. Dirk Herrmann Dirk Herrmann. Then you do that escaping thing again. Before I get to the major problem, there are two subsidiary ones: you don't need to escape the single-quotes in the string, and you do need to add a newline (\n) at the end (unlike echo, @OphirHarpaz, if you want to know if your changes are correct, use bash -x yourscript to see exactly what is being passed to curl (though that's shell-escaped, as opposed to byte-for-byte). txt Double quotes foo* As you can see, the results are completely different. Basics of Escaping Double Quotes. 01 (version on OS X El Capitan) and 6. What you describe trailing quote not removed means there is some invisible character like a space trailing the quote. 0. bash. Not sure when it was added but it is supported in 6. Shell script: single quote escaping. I want to put the variables, I got by read, in a file with cat << EOF >> file. teppic teppic. Unless I've done something wrong, that would seem to make this unsuitable for dealing with file names. Using double quotes we can expand the literal value of the variable by just prefixing the variable name with $ as said earlier for I want to run a command from a bash script which has single quotes and some other commands inside the single quotes and a variable. cURL in Bash - Passing Variables Between Single Quotes . That said, on a glance, what you're doing there looks good to me -- which is to say that it should be substituting in the variables in question; whether the result is a valid document I need to run a script with a string argument that includes single quotations mark and a variable. Alternatively: set variable nodeNumm to empty string for duration of the following, run the command, execute the output as a command. Hot Network Questions Travel booking concerns due to drastic price and option differences PDP11 'and' instruction The Honest, The Liar, And The Elusive You're just making this harder for yourself by trying to do it in shell (because you're always going to have issues dealing with quotes and whitespace in any non-trivial shell script). Here is simplified example of my problem (sh_param just prints all passed parameters): Without the double quotes around the variable, the internal spacing is lost and the expansion is treated as two arguments to the printf command. Follow answered Dec 5, 2014 at 3:58. ; When you use a variable without wrapping it in double-quotes, it'll try to split the value into separate words and also try to expand any wildcards into a list of matching filenames. But that didn't work. 31. Just include the double quotes within the string in the following . You will need to do this twice, once for the starting double quote and once for the end. hopefully a simple question and the last piece in my puzzle :-) I have a shell script running in terminal under os x. The unquoted text dn\'t contains a single quote that's escaped at the shell level, so it doesn't start a quoted string and is included as a literal character (so, dn't). This is appropriate for: Variable expansion: Double quotes allow the shell Always use double quotes around variables and wildcard expressions in your scripts to ensure consistent and predictable behavior. However, quotes also have special behavior where tokens expand within them. I want to pass that parameter to sed to replace an existing string with another which is composed of the variable: Variables are not expanded within single quotes. I tried also echoing the array into a variable, and echo removes the single quote, but then I'm not able to use the variable as an argument of mkvpropedit because the single quotes appear again Of course the script has to work also if the variable is a single word, such as LANG_NAME="eng". Personally, I find the style of over-quoting to be a bit excessive. if you have a parameter containing a single quote, the output from the above command will not cut and paste correctly. Also, this won't do anything if there's only a single leading quote or only a single trailing quote or if there are mixed quote Escape single quotes in shell script. It contains among other things: Put your newline in a variable, use the variable wherever you need a newline and change the quotes around your larger string to double quotes. This causes issues when trying to represent literal quotes: echo "double quote -> " <-- Terminates prematurely Why am I not able to detect if the file exist with this linux shell script? Related. As such, it has been written as a basis for one-on-one or group tutorials and exercises, and as a reference for subsequent use. – While it is correct that single (or triple single) quotes prevent interpolation in groovy, if you pass a shell command a single quoted string, the shell will perform parameter substitution, if the variable is an environment variable. Bash Script - Wrapping Variables in Quotes. Related. How can I prevent this? echo "Whats your name?" read yourname cat << EOF >> /path/to/file Your Name is "${yourname}" EOF The content of the file is: Following will convert all the single quotes to double quotes. to let a variable expand) or need to use no quotes (e. Follow edited Aug 23, 2021 at 12:59. Just use: Double quotes already escape single quotes. That's a single quote to end the single quoted string. cURL in Bash - Passing Variables Between Single Quotes. So what I need to do is call the variable such that it's value is swapped into the function and wrapped with double-quotes("), but avoid the name of the variable being read as a literal string. Either you can do like William suggests, or you can rewrite the line into double quotes, which will expand the variable as you want. @Kellyson variable expansion does not happen inside single-quotes, so you can not use single quotes here. From section 2. [1] Double-quotes are optional, ONLY IF the literal part of your RHS (the value to assign) contains neither whitespace nor other shell metacharacters. If you had a target system with a shell which didn't support extensions to POSIX such as $'', this guarantee would no longer be available, and External programs typically take care of removing enclosing double-quotes around parameters, but, as noted, in batch files you have to do it yourself (e. I have a input text file with 10 columns, while processing this file, in one of the middle column, I am getting this type of data. and then it gets even more complicated if RC_CONV_SET_VARS is not a literal filename but a variable name. The second command will not work (as expected), as you point out, because the shell would not expand the value of the variable I am trying to run a command in shell script which demands its argument to be passed in below format which includes double quotes with string. I'm trying to write a bash script, and I'm running into a quoting problem. To get rid of that too, use Trim('" ') or chain two Trim's together like. I know the question is about bash but for POSIX compatible system where the string must contain both single and double quotes you have to mix between both without spaces in between. Interpreting a quote in an argument is almost never a good idea because a quote should only be a means of delimiting an argument - and at invocation that As a general rule, I will always quote variable expansions even when I know the value won't contain any IFS characters because I want to be in the habit. How to use a variable in bash between ' ' See more linked questions. An unquoted, but escaped, single quote. At the base of it, the reality is that programmers are not serious about shell scripting as much as other scripting languages like Python and Ruby. e. Always show what you've tried. Thanks a lot. further complicated depending on whether RC_CONV_SET_VARS is local to your system or to the remote system. With that, you also don't need the backslashes before Also, if the contents of the variable are not quoted and contain a space, this seems to truncate everything after the first space. NOT an environment variable. If you add anything else in the quotes the Escaping double quotes in a variable in a shell script. When the shell expands a variable on the command line, if the variable was in double-quotes it's not parsed; if it was not in I have the following bash script: set -ex X="bash -c" Y="ls -al" I want to execute (notice the double quotes): bash -c "ls -al" The following does not work: In your first command, you are quoting the variable. With alias foo=`command`, command will be executed each time the alias is run. However, no matter how I try to escape the quotes it is not passed correctly. flv Obviously, ${date} won't expand in single quote, please also note that there is a double quote beyond the single quote, which makes it even more complicated. It's much easier to write a simple throwaway script, scp it to the remote host, and then run it there with ssh. /script. How to echo variables inside an ANSI A quoted here-document is the simplest way to do this (as in that other guy's comment and Barmar's answer), but if you really want to use printf, there are a couple of ways to do that. In short, quote everything where you do not require the shell to perform word What is really meant by the double quotes? Script1. My pet peeve is that everyone I've used single quotes to ensure that other shell metacharacters are not mishandled. When you enclose a string in double quotes, Bash will perform variable expansion and command substitution within the string. flv -vf drawtext="fontfile=Sans. The value of login_token variable should be passed without quotes as it is. ) This allows us to use old-style command substitution with backticks and variable substitution (dollar sign) within double quoted strings: You must include the variable PATH inside double quotes. I required column value to be as below: Input Column value: "This is my new program:"Hello The single quotes around the command and the backslashes in front of the double quotes interpret the quotes as characters in the command and not as special characters. I want to call external application from shell script, but this shell script gets parameters (from other script) in a single variable. I am on CentOS 6. set backslash_quote set sentence = 'I\'m a little teapot. not in assignment, then you'd need to quote. txt foo1. But in the following code: #!/bin/sh echo *. to do globbing and file name expansion). How to pass a double quoted value of a variable, as argument of the curl command, in a bash script? 3. I can't add an escape character because the json str is externally sent. Line 15 is a bit Double quotes: Double quotes are similar to single quotes except that it allows the shell to interpret dollar sign ($), backtick(`), backslash(\) and exclamation mark(!). Can someone please suggest the way to achieve it. The workaround is necessitated by single-quoted strings not supporting embedded single quotes at all; the '\'' part only makes sense "inside" a single-quoted string in that: Double Quotes. 5. awk -v s="'" '{gsub(s,"\"")}1' file OR Your shell is not passing the quotes through to the script. sh echo "*. To verify this fact, we’ll try to assign a sentence to a shell variable without quotes: command 'world' from Use double quotes ("") when you want to allow variable expansion but prevent word splitting and filename expansion. If your script's stdin is connected to your terminal you can manually look Yes, bash offers a way to do "double expansion" of a variable, aka, a way to first interpret a variable, then take that as the name of some other variable, where the other variable is what's to actually be expanded. There is another type of quote the shells support. This used awk's inbuilt gsub function to search and replace the text. 5,939 1 1 gold badge Also, a note about using $() and backticks in aliases. A double quote may be used within double quotes by preceding it with Short answer: see BashFAQ #50 ("I'm trying to put a command in a variable, but the complex cases always fail!"). If you are using Bash then include #!/bin/bash in the starting of the script and save your script as filename. With arrays, the rules are both similar and different. raju. $variable' In this format, $ is Note that COLUMNS is:. Follow answered Sep 2, 2012 at 22:32. Case 3: Escaping Double Quotes Enclosed in Single Quotes Without Variable Interpretation. 9. 4,968 17 17 gold badges 66 66 silver badges 121 121 bronze badges. sh 'test'. Improve this answer. 175k 31 31 gold badges 244 244 silver badges 287 287 bronze badges. Quoting. The end result I'm after is for my script to call: lwp-request -U -e -H "Range: bytes=20-30" My script file looks like: Check out Escape Single Quotes in PowerShell. Hot Network Questions How do I get the drain plug out of the sink? How to run a program over multiple sessions (machine off and on again) Will the first Mars mission force the space laundry question? What is this Door God saying? Always double quote variable expansions, unless you explicitly want the shell to perform word-splitting and filename generation (globbing) on the strings. If you are using sh then use #!/bin/sh and save your script as filename. Modified 8 years, 4 months ago. Then the quote is printed, overwriting the first character (which also happens to be a quote). There are also used to create files in a shell Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Use single (') and double quotes (") in bash shell scripts or when executing commands directly in the terminal to instruct the shell how to interpret certain characters. Single quotes will take the argument verbatim. It then gets interpreted again by the subshell. Take a look at the Advanced Bash Scripting Guide, specifically section 5. I also feel that you’re not telling us everything — maybe because you think it’s too obvious? Sometimes I copy and paste syntax and forget to match the variable generated by the read command with that actually used in the shell command, but that is not the case here. The "triple backslash" is actually ` \\ ` (escaped backslash) and \" (escaped double-quote) - The sh build step performs its own parameter expansion before shelling out, meaning that the the escaped quote is consumed by the process of building the command that will be passed to the shell. There are called Here is documents. ayo rkpear jiy qbybbes wwxssjmin dqrf ksnma iwopo dtfc dmvlv