diff options
Diffstat (limited to 'users/Profpatsch/lib.nix')
-rw-r--r-- | users/Profpatsch/lib.nix | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/users/Profpatsch/lib.nix b/users/Profpatsch/lib.nix new file mode 100644 index 000000000000..879d87755d56 --- /dev/null +++ b/users/Profpatsch/lib.nix @@ -0,0 +1,108 @@ +{ depot, pkgs, ... }: +let + bins = depot.nix.getBins pkgs.coreutils [ "printf" "echo" "cat" "printenv" "tee" ] + // depot.nix.getBins pkgs.bash [ "bash" ] + // depot.nix.getBins pkgs.fdtools [ "multitee" ] + ; + + # Print `msg` and and argv to stderr, then execute into argv + debugExec = msg: depot.nix.writeExecline "debug-exec" { } [ + "if" + [ + "fdmove" + "-c" + "1" + "2" + "if" + [ bins.printf "%s: " msg ] + "if" + [ bins.echo "$@" ] + ] + "$@" + ]; + + # Print stdin to stderr and stdout + eprint-stdin = depot.nix.writeExecline "eprint-stdin" { } [ + "pipeline" + [ bins.multitee "0-1,2" ] + "$@" + ]; + + # Assume the input on stdin is netencode, pretty print it to stderr and forward it to stdout + eprint-stdin-netencode = depot.nix.writeExecline "eprint-stdin-netencode" { } [ + "pipeline" + [ + # move stdout to 3 + "fdmove" + "3" + "1" + # the multitee copies stdin to 1 (the other pipeline end) and 3 (the stdout of the outer pipeline block) + "pipeline" + [ bins.multitee "0-1,3" ] + # make stderr the stdout of pretty, merging with the stderr of pretty + "fdmove" + "-c" + "1" + "2" + depot.users.Profpatsch.netencode.pretty + ] + "$@" + ]; + + # print the given environment variable in $1 to stderr, then execute into the rest of argv + eprintenv = depot.nix.writeExecline "eprintenv" { readNArgs = 1; } [ + "ifelse" + [ "fdmove" "-c" "1" "2" bins.printenv "$1" ] + [ "$@" ] + "if" + [ depot.tools.eprintf "eprintenv: could not find \"\${1}\" in the environment\n" ] + "$@" + ]; + + # Split stdin into two commands, given by a block and the rest of argv + # + # Example (execline): + # + # pipeline [ echo foo ] + # split-stdin [ fdmove 1 2 foreground [ cat ] echo "bar" ] cat + # + # stdout: foo\n + # stderr: foo\nbar\n + split-stdin = depot.nix.writeExecline "split-stdin" { argMode = "env"; } [ + "pipeline" + [ + # this is horrible yes but the quickest way I knew how to implement it + "runblock" + "1" + bins.bash + "-c" + ''${bins.tee} >("$@")'' + "bash-split-stdin" + ] + "runblock" + "-r" + "1" + ]; + + # remove everything but a few selected environment variables + runInEmptyEnv = keepVars: + let + importas = pkgs.lib.concatMap (var: [ "importas" "-i" var var ]) keepVars; + # we have to explicitely call export here, because PATH is probably empty + export = pkgs.lib.concatMap (var: [ "${pkgs.execline}/bin/export" var ''''${${var}}'' ]) keepVars; + in + depot.nix.writeExecline "empty-env" { } + (importas ++ [ "emptyenv" ] ++ export ++ [ "${pkgs.execline}/bin/exec" "$@" ]); + + +in +{ + inherit + debugExec + eprint-stdin + eprint-stdin-netencode + eprintenv + split-stdin + runInEmptyEnv + ; +} |