The maximum character length of arguments in a shell command depends on the operating system and the shell that you are using.
In most Unix and Linux systems, the maximum character length of arguments in a shell command is limited by the maximum size of the command line, which is typically determined by the maximum value of the ARG_MAX system parameter.
The ARG_MAX system parameter specifies the maximum size of the argument list (including the environment) that can be passed to the exec family of functions, which are used to execute programs in the shell.
To find out the value of the ARG_MAX system parameter on your system, you can use the getconf command, like this:
getconf ARG_MAX
This command will display the value of the ARG_MAX system parameter in bytes.
Keep in mind that the maximum character length of arguments in a shell command may also be limited by other factors, such as the maximum length of a command line that the shell can handle, or the maximum length of a command that the kernel can execute.
For example, in the bash shell, the maximum length of a command line is limited by the MAX_ARG_STRLEN constant, which is defined in the bash source code. The value of MAX_ARG_STRLEN is typically set to 131072 bytes (128 KB).
In the zsh shell, the maximum length of a command line is limited by the ARG_MAX system parameter, as in other shells.
In Linux, the maximum length of a command that the kernel can execute is limited by the MAX_ARG_STRLEN constant, which is defined in the Linux kernel source code. The value of MAX_ARG_STRLEN is typically set to 16384 bytes (16 KB).
It is generally recommended to avoid passing very long arguments to shell commands, as this can cause performance issues and may also be a security risk. Instead, you can use input redirection or pipes to pass long input to a command, or use a script to process the input and pass it to the command in smaller chunks.