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waitforssh(1) General Commands Manual waitforssh(1) NAME waitforssh -- Wait for a target to be up and running using SSH SYNOPSIS waitforssh [-C command] [-T command] [-d delay] [-r max-retries] target waitforssh -v DESCRIPTION waitforssh is a lightweight utility, written in POSIX shell, that waits for a target to be up and running via SSH and, if so, executes a command. -v Display version information about waitforssh. -C command Command to be executed when waitforssh successfully establishes a con- nection. By default, this parameter is set to true which means that the true utility will be executed on target. -T command Command to execute that controls the execution flow of waitforssh and, therefore, the exit status. When this command is the same as the one specified by the -C parameter, only this command is executed. By de- fault, true is the default test command. -d delay Before attempting to establish a connection and execute a command, waitforssh waits for as many seconds as specified in this parameter. The special value random which is the default value, is accepted to choose a random number between 1 and 10. See for more details on the syntax. -r max-retries Total number of retries before waitforssh exits with a non-zero exit status. ENVIRONMENT - WAITFORSSH_LOGLEVEL: Verbosity level that is used when logging messages from ssh(1). QUIET is the default value. - WAITFORSSH_STRICTHOSTKEYCHECKING: Controls how ssh(1) verifies a remote server's host key to prevent man-in-the-middle attacks. no is the default value. - WAITFORSSH_USERKNOWNHOSTSFILE: File storing a list of public SSH keys. /dev/null is the default value. EXIT STATUS waitforssh may fail for one of the following reasons: - EX_USAGE: The command was used incorrectly. - EX_DATAERR: An argument is incorrect. - EX_UNAVAILABLE A connection cannot be established. SEE ALSO ssh(1) sshpass(1) sysexits(3) ssh_config(5) AUTHORS JesAos Daniel Colmenares Oviedo <DtxdF@disroot.org> CAVEATS When waitforssh establishes a connection, it executes the true utility as the first command to check whether the remote system can be accessed. If the -C parameter is set to true, which is the default value, this operation is performed only once, but if a different value is specified, the speci- fied command is executed after running the true utility. The command speci- fied with the -C parameter does not affect the exit status in any way. All these operations use the -T parameter of ssh(1), so keep in mind that some utilities may not work correctly unless they are designed to be non- interactive utilities. Also note that this utility does not prevent keyboard-interactive authenti- cation for utilities such as sshpass(1) from working correctly. However, it is better to use public key authentication. BUGS If the utility true is not found on the remote system or returns a non-zero exit status, waitforssh retries as if it had failed when in fact it suc- ceeded. SECURITY CONSIDERATIONS waitforssh was designed for ephemeral environments that can be accessed se- curely (e.g.: via a VPN), which explains the default settings and parame- ters chosen, which may be considered insecure. This utility does not re- place utilities specialized in remote command execution, but only serves to wait for a remote device to be operational and nothing else. The fact that an arbitrary command can be executed with this utility is only a convenient feature in some cases. FreeBSD ports 15.quarterly November 09, 2025 waitforssh(1)
NAME | SYNOPSIS | DESCRIPTION | ENVIRONMENT | EXIT STATUS | SEE ALSO | AUTHORS | CAVEATS | BUGS | SECURITY CONSIDERATIONS
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