Shell implements an idiomatic Ruby interface for common UNIX shell commands.
It provides users the ability to execute commands with filters and
csh by using native facilities of Ruby.
In this example we will create three
tmpFile’s in three different
folders under the
sh = Shell.cd("/tmp") # Change to the /tmp directory sh.mkdir "shell-test-1" unless sh.exists?("shell-test-1") # make the 'shell-test-1' directory if it doesn't already exist sh.cd("shell-test-1") # Change to the /tmp/shell-test-1 directory for dir in ["dir1", "dir3", "dir5"] if !sh.exists?(dir) sh.mkdir dir # make dir if it doesn't already exist sh.cd(dir) do # change to the `dir` directory f = sh.open("tmpFile", "w") # open a new file in write mode f.print "TEST\n" # write to the file f.close # close the file handler end print sh.pwd # output the process working directory end end
This example is identical to the first, except we’re using
Processor#transact executes the given block against self, in
sh; our Shell object. Within the block we can substitute
cd, because the scope within the block uses
sh = Shell.cd("/tmp") sh.transact do mkdir "shell-test-1" unless exists?("shell-test-1") cd("shell-test-1") for dir in ["dir1", "dir3", "dir5"] if !exists?(dir) mkdir dir cd(dir) do f = open("tmpFile", "w") f.print "TEST\n" f.close end print pwd end end end
In this example we will read the operating system file
cupsd, and then output it to a new file relative to the
sh = Shell.new sh.cat("/etc/printcap") | sh.tee("tee1") > "tee2" (sh.cat < "/etc/printcap") | sh.tee("tee11") > "tee12" sh.cat("/etc/printcap") | sh.tee("tee1") >> "tee2" (sh.cat < "/etc/printcap") | sh.tee("tee11") >> "tee12"