I think the above sed command will remove all the spaces in the file. Making statements based on opinion; back them up with references or personal experience. Should mention, For those interested in this solution, my. Where is this place? How do I prompt for Yes/No/Cancel input in a Linux shell script? Get app's compatibilty matrix from Play Store. Please people, like @codeforester, keep it simple; the best software always is. How can I check if a program exists from a Bash script? I have a script that separates the input string into an array my problem is that I want to check determine if the array element is whitepace or empty do something like a substitution. How do I convert a String to an int in Java? I even checked older bash and it's still wrong there; like you say set -x shows how it expands. If the file is not empty then the job script should abend. eg. Check if File Exists When checking if a file exists, the most commonly used FILE operators are -e and -f. The first one will check whether a file exists regardless of the type, while the second one will return true only if the FILE is a regular file (not a directory or a device). From the Linux and Unix bash(1) man page: nullglob If set, bash allows patterns which match no files to expand to a null string, rather than themselves. How to find out if a preprint has been already published. Removing/renaming multiple files containing spaces is a bit difficult task. @nhed: In the case of single characters, you can use a character pattern instead of the pipe character alternation. They can't be used on the right or the regex is changed to a literal string. Usually your not only interested in detecting the space character. --noprofile Do not read either the system-wide startup file /etc/profile or any of the personal initialization files ~/.bash_profile, ~/.bash_login, or ~/.profile. Otherwise, removal not including lines with spaces/tabs, use: grep . For reasons obvious above, it's better to put the regex in a variable: And quotes aren't necessary inside double square brackets. In Europe, can I refuse to use Gsuite / Office365 at work? grep "\S" file.txt Note: If you get unwanted colors, that means your grep is aliases to grep --color=auto (check by type grep). Following is the syntax of reading file line by line in Bash using bash while loop : Syntax How to mkdir only if a directory does not already exist? rev 2021.1.8.38287, Stack Overflow works best with JavaScript enabled, Where developers & technologists share private knowledge with coworkers, Programming & related technical career opportunities, Recruit tech talent & build your employer brand, Reach developers & technologists worldwide. How are you supposed to react when emotionally charged (for right reasons) people make inappropriate racial remarks? bash if -f : Check if file exists and is a regular file if statement when used with option f , returns true if the length of the string is zero. You could do this, without the need for any backslashes or external commands: The portable way to do this is with grep: ...a bit ugly, but guaranteed to work everywhere. However, any line which contains whitespace will not be considered empty. To learn more, see our tips on writing great answers. Navigating to a directory with spaces in the directory name. To navigate to a directory with spaces … Angular momentum of a purely rotating body about any axis. This page shows how to find out if a bash shell variable is empty or not using the test command. Therefore the continue solution is always recommended. cleanest one IMO, for me I also added tab but looks a little funky as I had to throw the dollar-quote in there. Check if folder /data/ is empty or not using bash only features. for mentioning spaces some of the commands.. For example if we take “for loop” to convert all the files in a given directory we will face issue, because for loop will take space as a separator between given entries We will use -a operator which is used to check folder existence and returns true if the given file exists. Do I have to include my pronouns in a course outline? If you write myfiles="file1 file2", with spaces to separate the files, this can't work with file names containing spaces. The -n operator checks whether the string is not null. Why do password requirements exist while limiting the upper character count? I am trying to run the following shell script which is supposed to check if a string is neither space nor empty. Check if File Exists and Not Empty. Writing setup, CI and deployment flows means a bit of the old bash scripting. Create a Bash script which will accept a file as a command line argument and analyse it in certain ways. Are Random Forests good at detecting interaction terms? 2. Join Stack Overflow to learn, share knowledge, and build your career. To "delete all blank spaces" can mean one of different things: delete all occurrences of the space character, code 0x20. suggested edits that add things, please post your own answers instead – this answers the original question as it is, and works quite universally regardless of the shell, so I don't think the answer is improved by complicating it with more cases for specific shells and/or needs beyond the original question, More information about the square bracket notation can be found at. Here is a simple script to pass a file path to ls or chmod but filenames with spaces don't work even when enclosed in quote marks. @ codeforester, keep it simple ; the best software always is will be using file! 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