NAME

       entr — run arbitrary commands when files change

SYNOPSIS

       entr [-cdpr] utility [argument ...] [/_]

DESCRIPTION

       A  list  of files provided on the standard input and the utility is executed using the supplied arguments
       if any of them change.  entr waits for the child process to finish before responding to  subsequent  file
       system  events.   A  TTY  is  also  opened before entering the watch loop in order to support interactive
       utilities.

       The arguments are as follows:

       -c      Execute /usr/bin/clear before invoking the utility specified on the command line.

       -d      Track the directories of regular files provided as input and exit if a new file is  added.   This
               option  also enables directories to be specified explicitly.  Files with names beginning with ‘.’
               are ignored.

       -p      Postpone the first execution of the utility until a file is modified.

       -r      Reload a persistent child process.  SIGTERM is  used  to  terminate  the  utility  before  it  is
               restarted.  A process group is created to prevent shell scripts from masking signals.  entr waits
               for the utility to exit to ensure that resources such as sockets have been closed.

       The first occurrence of /_ on the command line will be replaced with the absolute path of the first  file
       that was modified.  If the restart option is used the first file under watch is treated as the default.

ENVIRONMENT

       If  PAGER  is  undefined,  entr  will  assign  /bin/cat to prevent interactive utilities from waiting for
       keyboard input if output does not fit on the screen.

EXIT STATUS

       The entr utility exits with one of the following values:

             0       SIGINT or SIGTERM was received
             1       No regular files were provided as input or an error occurred
             2       A file was added to a directory while using the while using the directory watch option

EXAMPLES

       Rebuild a project if source files change, limiting output to the first 20 lines:

             $ find src/ | entr sh -c 'make | head -n 20'

       Launch and auto-reload a node.js server:

             $ ls *.js | entr -r node app.js

       Clear the screen and run a query after the SQL script is updated:

             $ echo my.sql | entr -p psql -f /_

       Rebuild project if a source file is modified or added to the src/ directory:

             $ while sleep 1; do ls src/*.rb | entr -d rake; done

Debian                                           March 13, 2015                                          ENTR(1)