A minimal Posix-compatible file synchronization utility built on rsync.
Download the file sync.sh in this repository and move it to
a permanent directory, renaming it if appropriate / desired.
In the shell, type source <path to sync script>.
The default configuration script will walk through the process for
setting up the sync command on the local machine.
This file provides a command-line function sync for
synchronizing a local directory with a server directory through
ssh and rsync. It keeps track of a file called .sync_time
containing the time since the Epoch in seconds to determine which
files are recently modified. Then the rsync utility is used to
transfer (and delete if appropriate) files between
$SYNC_LOCAL_DIR and $SYNC_SERVER:$SYNC_SERVER_DIR using the
efficient delta method of rsync. This can be very fast even for
large directories, certainly more so than a full scp.
This tool provides a one-liner replacement for something like
Dropbox or Git that can be used easily from a server with a POSIX
compliant shell with the commands whoami, hostname, pwd,
cd, rm, mkdir, dirname, basename, which, source,
export, read, echo, typeset, cat, wc, sed, grep,
ssh, ssh-keygen, ssh-copy-id, rsync, and python (or
python3).
$(<command to execute>)
${<string>:-<value if string is empty>}
${<string>%<pattern to remove from end of string>}
${<string>#<pattern to remove from beginning of string>}
${#<string to measure length>}
${<string>:<integer slice from>:<integer slice to>}
<command-1> | <command taking input from command-1 as a file>
<command> > <stdout redirect> 2> <stderr redirect>
[ <conditional expression to evaluate> ]
[ <conditional or 1> || <conditional or 2> ]
[ <integer is equal> -eq <to this integer> ]
[ <integer is greater> -gt <than this integer> ]
[ -f <this file exists?> ]
[ -d <this directory exists?> ]
[ ! <conditional to be negated> ]
func () { <body of function that takes arguments as $1 ...> }
while <loop condition> ; do <body commands> ; done
if <condition> ; then <true body> ; elif <condition> ; then <true body> ; else <false body> ; fi
Along with the standard POSIX expectations above, the following commands are used by this program with the demonstrated syntax.
whoami (no arguments / prints the current user name)
hostname (no arguments / prints name of machine)
pwd (no arguments / prints full path to present working directory)
cd <directory to move to>
rm -f <path to file to remove>
mkdir -p <directory to create if it does not already exist>
dirname <path to get only directory name>
basename <path to get only file name>
which <name of executable to return full path to>
source <path to shell file to run>
export <varname>=<value>
read <variable> (user input prompted with directory tab-auto-complete)
echo "<string to output to stdout>"
typeset -f "<name of shell function>"
cat <path to file that will be printed to stdout>
wc -l <path to file to show line count>
sed -i.backup "s/<match pattern>/<replace pattern in-file>/g" <file-name>
grep "<regular expression>" <file to find matches>
rsync -az -e "<remote shell command>" --update --delete --progress --existing --ignore-existing --dry-run <source-path> <destination-path>
python -c "<python 2 / 3 compatible code>"
ssh <server-name> "command" (opens a secure shell to server and runs command)
ssh-keygen (generates an ssh remote login key if it doesn't exist)
ssh-copy-id <server-name> (exchanges ssh authorizations with server)
$ sync [--status] [--configure] [--rename] [--help]
The sync command will synchronize the entire local directory if
no path nor options are specified. If a path is specified, it
must be contained within $SYNC_LOCAL_DIR and only that subset
will be synchronized.
Executing with the --status option will get the last
modification time of the server and local directories, print them,
and exit.
Executing with the --configure option will run the initial
configuration script to update the stored configuration variables
expressed in the local sync script.
Executing with the --rename option will prevent the script from
exiting upon discovery of local conflict files. Instead, the local
files will be renamed appropriately and then synchronization will
continue as normal.
Executing with the --help option will display an abbreviated
version of this documentation to standard output.
A script is provided that will automatically walk you through
configuration on your local host. If this file is executed and
the value $SYNC_SCRIPT_PATH does not point to a valid file, a
prompt to automatically (re)configure will appear.
In some cases, symbolic links will show a modification time that
makes them always synchronize. This can cause chaos, so for now
if you see this happenn then delete that file. Please consider
submitting an Issue in the repository with a minimum working
example and I will fix it as soon as possible.