|0.1.1||Mar 29, 2023|
|0.1.0||Mar 29, 2023|
#688 in Command line utilities
waitfor is a command-line utility that executes another command repeatedly,
until it exits with a zero exitstatus.
The basic usage is:
# Wait for a file to be downloaded successfully. waitfor curl -O http://example.com/file.tar.gz # Wait for a remote host to respond to a ping. waitfor ping -c 1 -t 1 192.168.1.42 # Wait for a FIFO socket file to appear on disk. waitfor test -f /tmp/mysql.sock
waitfor will run the command with a linear delay of 100ms between
invocations. This can be adjusted with the
-d options (in
waitfor forwards all standard output and error to its standard output and
Backoff and Timeout
waitfor can be configured with two types of delays between attempts.
- Linear delay (
-l, default) will pause a number of milliseconds (specified by
-d) between executions.
- Exponential backoff (
-b) will start with the inital delay (
-d) and increase at a provided rate (
In all cases, the delay is calculated after an attempt completes, not from the time an attempt is started, so it cannot guarentee a rate of requests because that is dependent on the time an individual attempt takes.