Check if bash or csh

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WebAug 3, 2024 · Using if-else to check whether two numbers are equal When trying to understand the working of a function like if-else in a shell script, it is good to start things simple. Here, we initialize two variables a and b, then use the if-else function to check if the two variables are equal. The bash script should look as follows for this task. WebThe easiest way to do that is with pstree: if pstree -s -p $$ grep -c '\-sshd (' >/dev/null; then echo "SSH session" else echo "regular session" fi. Explanation: The $$ gives the currently running process PID. pstree -s -p $$ creates a single line listing of the process tree.

How to Use if-else in Shell Scripts? DigitalOcean

WebFeb 6, 2012 · The following example reduces it to 5 seconds: ssh -o ConnectTimeout=5 -q user@downhost exit. – grim_i_am. Mar 31, 2024 at 9:41. Show 5 more comments. 33. You can use something like this. $ (ssh -o BatchMode=yes -o ConnectTimeout=5 user@host echo ok 2>&1) This will output "ok" if ssh connection is ok. WebAug 26, 2024 · How to check which shell am I using: Use the following Linux or Unix commands: ps -p $$ – Display your current shell name reliably. echo "$SHELL" – Print the shell for the current user but not … sbt book physics

csh - C Shell script condition for if string contains a newline ...

WebSep 17, 2024 · We can use regular expressions in Bash using [ [ STRING =~ REGEX ]]. This command returns the value 0 if the regular expression matches. Otherwise, it returns the value 1. As we need this behavior in the exist_in_list function, we can run the [ [ ]] command without any explicit return command. WebAug 6, 2024 · If you also want to match when the number is the last one on the line, so it has no , after it, you can use grep -E to enable extended regular expressions and then match either a 329 followed by a comma ( 329,) or a 329 that is at the end of the line ( 329$ ). You can combine those like this: WebCheck for $BASH_VERSION, $ZSH_VERSION, and other shell-specific variables. Check $SHELL; this is a last resort, as it specifies your default shell and not necessarily the current shell. Share Improve this answer edited Sep 11, 2024 at 8:05 tomglynch 103 3 answered Mar 18, 2011 at 2:12 geekosaur 31.1k 5 79 57 8 Should you mention $0 too? … sbt brighton

remote - Am I using bash or sh? - Ask Ubuntu

WebMay 16, 2024 · 1 If you are working in a tcsh (often installed as csh on Linux), then if ( -l "$link") should work. The -l operator checks if a file is a symbolic link. I don't think there is an build-in equivalent in the plain csh. Share Improve this answer Follow answered May 16, 2024 at 12:01 Lars 126 2 Add a comment Your Answer WebSep 18, 2016 · If the remote OS is Ubuntu (or another GNU/Linux based distribution), a very simple way to figure out what shell you are running is to run this command: ls -l /proc/$$/exe if the remote OS is not Ubuntu or at least a similar GNU/Linux distribution, you asked in the wrong site. sbt boxWebAug 28, 2024 · Alternatively, you can use the $status variable: grep -q 'Pattern' file if ( $status == 0 ) then echo "Pattern found" else echo "Pattern not found" endif In tcsh, the variable $status may be replaced by $? - but not all csh implementations appear to support this. Share Improve this answer Follow edited Aug 28, 2024 at 15:47 sbt bottighofen

"WebFeb 13, 2024 · Simply execute the command: $ ps From the first line of the output, we can clearly see the PID of the shell and the last column prints out the type of shell, in this case - bash. Alternatively, you can run the command: $ ps -p $$ You can also use ps -p $$ -o args= which output just the shell name. 3. By viewing /etc/passwd file " - Check if bash or csh

Check if bash or csh

How to Use if-else in Shell Scripts? DigitalOcean

WebNov 2, 2005 · if in csh I am using this code echo "opt_tpath = $opt_tpath" if ($opt_tpath == 1) echo " -tpath = $Atpath\n" and is giving opt_tpath = 0 Atpath: Undefined variable. Atpath should only be printed in opt_tpath == 1 but it still tries to print. ---------- Post updated at 10:05 AM ----------... 7. UNIX for Dummies Questions & Answers csh WebAug 3, 2024 · 1. Using if-else to check whether two numbers are equal. When trying to understand the working of a function like if-else in a shell script, it is good to start things simple. Here, we initialize two variables a and b, then use the if-else function to check if the two variables are equal.

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WebJan 18, 2024 · Syntax to find out if file exists with conditional expressions in a Bash Shell The general syntax is as follows: [ parameter FILE ] OR test parameter FILE OR [ [ parameter FILE ]] Where parameter can be any one of the following: -e: Returns true value if file exists. -f: Return true value if file exists and regular file. WebNov 20, 2024 · 2 Answers Sorted by: 1 Use ` (back-quote) to assign an output from a system command. And, grep returns 0 if the match is found, and 1 if it's not. You can test this by running the specific regex and print the output with echo $? So the correct syntax is;

WebTo check if you are in a login shell: shopt -q login_shell && echo 'Login shell' echo 'Not login shell' By "batch", I assume you mean "not interactive", so the check for an interactive shell should suffice. Share Improve this answer edited Sep 29, 2024 at 9:28 answered Dec 13, 2011 at 23:19 Chris Down 120k 22 263 260 28 WebSep 18, 2016 · So a simple script like this: #!/bin/bash echo $0. Will give output like this: $ ./test_script.sh ./test_script.sh. This is also apparent when you do something like this: $ echo 'one two three' xargs bash -c 'echo $0' one. For all shells , -c option places first command line argument into $0 variable. As far as interactive shell goes, $0 ...

WebFeb 26, 2024 · Passing parameters to a script [edit edit source]. In scripts, the variables $0, $1, $2, and so on are known as positional parameters.The variable $0 refers to the name of the command and $1, $2 and greater will be the parameters passed into the script.. When a csh script is invoked, the special variable argv is set to the wordlist of arguments given …

WebDec 6, 2015 · All you have to do is type shell name to start using it: $ csh OR $ tcsh Advertisement Install csh / tcsh In case csh is not installed, type the following command at shell prompt as per your Linux distro / version. Install it on Debian/Ubuntu/Mint Linux $ sudo apt-get install csh Install it on CentOS/RHEL # yum install tcsh

WebJun 13, 2024 · It works as a "switch" statement in other languages ( bash, zsh, and ksh93 also allows you to do fall-through in various incompatible ways). The patterns used are the standard file name globbing patterns. The issue you are having is due to the fact that _ is a valid character in a variable name. sbt breathing trialWebJun 26, 2015 · For ksh, zsh and bash, a potentially better approach could be: if ( ($ {#var [@]})); then echo '$var (or the variable it references for namerefs) or any of its elements for array/hashes has been set' fi For ksh93, zsh and bash 4.4 or above, there's also: if typeset -p var 2> /dev/null grep -q '^'; then echo '$var exists' fi sbt breathingWebif ($mystr:q =~ *'\ '*) echo yes should work in some implementations and versions of csh (like the csh and tcsh ones found on Debian). In some others (like the one found on Solaris 10), you may have better luck with set nl = '\ ' if ($mystr:q =~ *$nl:q*) echo yes Most people have given up trying to write reliable scripts with csh by now. sbt buildinfopluginWebchsh (an abbreviation of "change shell") is a command on Unix-like operating systems that is used to change a login shell.Users can either supply the pathname of the shell that they wish to change to on the command line, or supply no arguments, in which case chsh allows the user to change the shell interactively. sbt build toolWebMar 28, 2024 · Here, we discuss five ways by which we can check which shell we are using. 1) Using echo command: Basically, the echo command is used to print the input string, but it is also used to print the name of the shell which we are using with the help of the … sbt broadcastWebJan 16, 2014 · You can find a very nice reference for bash's operators here. If you are using a different shell, just search for operators and you will find everything you need. In your particular case, you are using: -n string is not null. -z string is null, that is, has zero length To illustrate: sbt bracesWebFeb 28, 2015 · To find the current shell instance, look for the process (shell) having the PID of the current shell instance. $SHELL is the default shell for the system (or user), which is usually (but not necessarily) the shell that is actually being used at any given moment. @kingmilo: Right you are, answer modified. sbt cache