Alexander Medvednikov
0355826d9f
* driver: forward termination signals to run children * cgen: embed run signal helpers in portable snapshots * driver: terminate inherited run child handlers before exec * driver: preserve signal dispositions and pending termination * driver: isolate run signal delivery while preserving job control * driver: relay terminal interrupts to output pipeline peers * driver: relay caught terminal stops and clean failed run groups * cache: track all embedded native helper inputs
2.2 KiB
Running inline V code
Use v -e 'println(1)' or v -e='println(1)' to compile and run a short V script.
Imports and top-level statements work just as they do in a .vsh file.
Compiler options go before -e. Arguments after the code are passed to the program,
including compiler command names and flags such as version, doc, and --help:
v -prod -e 'import os; println(os.args[1..])' first 'with spaces'
The command returns the program's exit status. A temporary source file in the current
working directory and the implicit executable are removed when the compilation or program
finishes, including when interrupted with Ctrl-C or Ctrl-\.
On Unix, the program runs in a separate process group. Handled signals sent to V's
group are forwarded once. V forwards SIGTERM, SIGHUP, SIGINT, and SIGQUIT and waits for the
program before removing temporary files. After SIGTERM or SIGHUP, V exits with
128 + signal. Signals inherited as ignored remain ignored, including SIGHUP under nohup.
Interactive programs receive the foreground terminal while running. Terminal input and
shell job control (Ctrl-Z, fg, and bg) continue to work. Terminal interrupts also reach
peers in an output pipeline, even if the program handles the interrupt and keeps running.
Terminal Ctrl-Z also suspends the original pipeline when the program catches or ignores
SIGTSTP. Failed signal setup terminates the verified program group, including its descendants.
Catchable job-control stop signals
sent to V are forwarded to the program. Uncatchable SIGKILL and SIGSTOP sent only to V
cannot be forwarded to the separate program group. With piped or redirected stdin, the
original job keeps the foreground terminal so pipeline peers can read it. A program that
opens /dev/tty directly in this configuration runs in a background group and may stop
when accessing that terminal.
Use v -http to serve the current directory on localhost:4001. This is equivalent to:
v -e 'import net.http.file; file.serve()'
For another directory or port, pass file.serve options in the inline source:
v -e 'import net.http.file; file.serve(folder: "/tmp", on: ":5002")'