at:tldr:b0993

The command

echo "${--make_db_backup-sh}" | at 1000

is used to schedule the execution of a command at a specific time using the at command.

Here is a breakdown of the command:

• echo "${--make_db_backup-sh}": This part of the command is responsible for generating the text that will be executed at the specified time. "${--make_db_backup-sh}" is a variable or a command substitution enclosed in double quotes ${}. This part is specific to the system and depends on the context in which the command is used. It could be a variable containing a command or an option for the at command.

• |: The pipe character | is used to redirect the output of the command on the left side to the input of the command on the right side. In this case, the output of the echo command will be passed as input to the at command.

• at 1000: This part of the command specifies the time at which the command should be executed. 1000 represents the time in the format HHMM (hours and minutes) in a 24-hour clock format. In this example, it represents 10:00 AM. The at command will then read the input from the previous command and schedule its execution at the specified time.

Overall, this command is used to schedule the execution of a command specified by the ${--make_db_backup-sh} variable or command substitution at 10:00 AM.