diff --git a/run-command.h b/run-command.h
index 1fc781d7668468f9e74bd430b7569dc040440ba8..debe3074b5a01fb5a19e61f07ff66c250cdc4f82 100644 (file)
--- a/run-command.h
+++ b/run-command.h
struct child_process {
const char **argv;
pid_t pid;
+ /*
+ * Using .in, .out, .err:
+ * - Specify 0 for no redirections (child inherits stdin, stdout,
+ * stderr from parent).
+ * - Specify -1 to have a pipe allocated as follows:
+ * .in: returns the writable pipe end; parent writes to it,
+ * the readable pipe end becomes child's stdin
+ * .out, .err: returns the readable pipe end; parent reads from
+ * it, the writable pipe end becomes child's stdout/stderr
+ * The caller of start_command() must close the returned FDs
+ * after it has completed reading from/writing to it!
+ * - Specify > 0 to set a channel to a particular FD as follows:
+ * .in: a readable FD, becomes child's stdin
+ * .out: a writable FD, becomes child's stdout/stderr
+ * .err > 0 not supported
+ * The specified FD is closed by start_command(), even in case
+ * of errors!
+ */
int in;
int out;
int err;
const char *dir;
const char *const *env;
- unsigned close_in:1;
- unsigned close_out:1;
unsigned no_stdin:1;
unsigned no_stdout:1;
unsigned no_stderr:1;