INSITU(1) General Commands Manual INSITU(1)
NAME
insitu - modify files in place with shell commands
SYNOPSIS
insitu [-t] file command
DESCRIPTION
A shell pipeline cannot both read and write to the same file; for
example
cat foo | grep bar > foo
will merely delete the contents of foo.
Insitu wraps a shell command, connecting its standard input and
standard output to the file. If command finishes successfully, the
file will be truncated (or extended) to the size of the output produced
by the command. If command returns a non-zero exit status, the file
will not be truncated (unless -t is passed), but contain the output
read from the command, followed by the rest of the original file. The
part of the file overwritten by the command output will be lost.
Insitu runs the command with '$SHELL -c command', substituting /bin/sh
for $SHELL if the latter is not set.
Options
-t truncate file even if command returns a non-zero exit status.
EXIT STATUS
insitu returns the exit status of command. Additionally, 128 is
returned if invalid flags are passed, 129 if file cannot be accessed,
and 130 if the child process for running command cannot be started.
BUGS
Insitu is a dangerous and brittle tool that can easily cause data
corruption if the command fails halfway through. Make sure you
understand this risk before running it on important files.
SEE ALSO
cp(1),mv(1),sh(1)
insitu-1.0 INSITU(1)