I quite like the idea. Here's an example implementation of a flag that
could be used in a shell function/alias, if that's your thing. Comments?
On Sun, Apr 17, 2016 at 9:12 PM, Bernhard Voelker <m...@bernhard-voelker.de>
wrote:
> On 04/10/2016 04:26 PM, 積丹尼 Dan Jacobson wrote:
> >>>>>> "BV" == Bernhard Voelker <m...@bernhard-voelker.de> writes:
> > BV> Well, there are many possibilities, but there is already a way to
> > BV> to do it in xargs. So what would you want to achieve by saving a
> RET?
> > BV> I don't think it's about the wearing of the ENTER key on your
> keyboard?
> >
> > Thank you. If there is a way to do
> > $ seq 99|sed s/^/URL_/|xargs -pn 9 $BROWSER
> > so I can browse 9 items at a time
> > with just hitting RET instead of y RET, please tell me.
>
> I'd personally go with some shell loop like:
>
> seq 99|sed s/^/URL_/|xargs -n9 \
> | while read urls; do \
> read -p "$urls:" </dev/tty; \
> $BROWSER $urls; \
> done
>
> Of course, as the URLs may contain some special characters, you'd have
> to care about proper quoting or escaping/unescaping additionally.
>
> Nevertheless, xargs isn't primarily a tool to get and evaluate
> the user's approval to execute arbitrary tools; and I don't think
> it should support more ways of evaluating such approval.
>
> Have a nice day,
> Berny
>
>
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From bfea9c150229db14316262c1c05198c7caeb9538 Mon Sep 17 00:00:00 2001
From: James Youngman <j...@gnu.org>
Date: Sat, 16 Jul 2016 15:10:32 +0100
Subject: [PATCH] xargs: add new option --interactive-default-yes, modifying
--interactive.
To: findutils-patc...@gnu.org
* xargs/xargs.c: Add a new static boolean interactive_default_yes
which is set when the --interactive-default-yes option is in effect.
(longopts): add --interactive-default-yes.
(main): Set interactive_default_yes when --interactive-default-yes
is used.
(xargs_do_exec): Pass interactive_default_yes to print_args.
(print_args): Accept just RETURN as being a positive response when
interactive_default_yes is in effect. Also specify /dev/tty in the
error message when we fail to read from it, instead of incorrectly
stating that we failed to read from stdin.
(usage): Mention --interactive-default-yes.
* xargs/xargs.1: Document the new option --interactive-default-yes.
* doc/find.texi (Querying): Document --interactive-default-yes.
(xargs options): Likewise.
* NEWS: Mention this improvement.
---
NEWS | 5 +++++
doc/find.texi | 16 ++++++++++++++++
xargs/xargs.1 | 13 ++++++++++++-
xargs/xargs.c | 31 +++++++++++++++++++++----------
4 files changed, 54 insertions(+), 11 deletions(-)
diff --git a/NEWS b/NEWS
index bccb19a..251a527 100644
--- a/NEWS
+++ b/NEWS
@@ -35,6 +35,11 @@ of the - yet more portable - '( -type l -o -type d )'.
find now diagnoses failures returned by readdir(). This bug was inherent
in the use of FTS.
+The new option --interactive-default-yes for xargs modifies the way
+that xargs behaves when the user's response is just to press the
+return key. Without this option (and before this change) the command
+is not run. With this option, the command is run.
+
** Bug Fixes
#48180: find -noop (an internal option not intended to be exposed to the user)
diff --git a/doc/find.texi b/doc/find.texi
index b3c5d10..546ef00 100644
--- a/doc/find.texi
+++ b/doc/find.texi
@@ -2772,6 +2772,15 @@ from the terminal. Only run the command line if the response starts
with @samp{y} or @samp{Y}. Implies @samp{-t}.
@end table
+@table @code
+@item --interactive-default-yes
+Normally a response @samp{y} or @samp{Y} is required for
+@samp{--interactive} to run the command. When
+@samp{--interactive-default-yes} is specified, just pressing return
+has the same effect as pressing @samp{y} then return.
+This option does not imply @samp{--interactive}.
+@end table
+
@node Delete Files
@section Delete Files
@@ -3729,6 +3738,13 @@ terminate arguments; instead, the input is split at newlines only. If
Implies @samp{-x} and @samp{-l 1}. The @samp{-i} option is deprecated
in favour of the @samp{-I} option.
+@item --interactive-default-yes
+Normally a response @samp{y} or @samp{Y} is required for
+@samp{--interactive} to run the command. When
+@samp{--interactive-default-yes} is specified, just pressing return
+has the same effect as pressing @samp{y} then return. Does not imply
+@samp{--interactive}.
+
@item -L @var{max-lines}
@itemx --max-lines@r{[}=@var{max-lines}@r{]}
@itemx -l@r{[}@var{max-lines}@r{]}
diff --git a/xargs/xargs.1 b/xargs/xargs.1
index 6837786..024dfd1 100644
--- a/xargs/xargs.1
+++ b/xargs/xargs.1
@@ -25,6 +25,7 @@ xargs \- build and execute command lines from standard input
[\fB\-\-max\-procs\fR=\fImax-procs\fR]
[\fB\-\-process\-slot\-var\fR=\fIname\fR]
[\fB\-\-interactive\fR]
+[\fB\-\-interactive-default-yes\fR]
[\fB\-\-verbose\fR]
[\fB\-\-exit\fR]
[\fB\-\-no\-run\-if\-empty\fR]
@@ -178,6 +179,16 @@ This option is deprecated; use
.B \-I
instead.
.TP
+.PD
+.B \-\-interactive\-default\-yes
+When the
+.B \-\-interactive
+option is in effect and the user simply
+presses return in response to the prompt, behave as if they had
+responded positively. If you want the prompting behaviour, you
+will also need to specify
+.BR \-\-interactive .
+.TP
.BI \-L " max-lines"
Use at most \fImax-lines\fR nonblank input lines per command line.
Trailing blanks cause an input line to be logically continued on the
@@ -255,7 +266,7 @@ otherwise use separate resources).
.B \-p, \-\-interactive
Prompt the user about whether to run each command line and read a line
from the terminal. Only run the command line if the response starts
-with `y' or `Y'. Implies
+with `y' or `Y' (though see also \-\-interactive\-default\-yes). Implies
.BR -t .
.TP
.PD
diff --git a/xargs/xargs.c b/xargs/xargs.c
index 5cf8c13..2fd2904 100644
--- a/xargs/xargs.c
+++ b/xargs/xargs.c
@@ -158,6 +158,10 @@ static bool print_command = false; /* Option -t */
execute the command if the user responds affirmatively. */
static bool query_before_executing = false;
+/* If true, if the user just types RETURN in response to a query from -p,
+ * behave as if they had responded 'y' (instead of 'n'). */
+static bool interactive_default_yes = false;
+
/* The delimiter for input arguments. This is only consulted if the
* -0 or -d option had been given.
*/
@@ -173,7 +177,8 @@ static char* slot_var_name = NULL;
enum LongOptionIdentifier
{
- PROCESS_SLOT_VAR = CHAR_MAX+1
+ PROCESS_SLOT_VAR = CHAR_MAX+1,
+ INTERACTIVE_DEFAULT_YES_OPT
};
static struct option const longopts[] =
@@ -186,6 +191,7 @@ static struct option const longopts[] =
{"max-lines", optional_argument, NULL, 'l'},
{"max-args", required_argument, NULL, 'n'},
{"interactive", no_argument, NULL, 'p'},
+ {"interactive-default-yes", no_argument, NULL, INTERACTIVE_DEFAULT_YES_OPT},
{"no-run-if-empty", no_argument, NULL, 'r'},
{"max-chars", required_argument, NULL, 's'},
{"verbose", no_argument, NULL, 't'},
@@ -215,7 +221,7 @@ enum ClientStatusValues {
static int read_line (void);
static int read_string (void);
-static bool print_args (bool ask);
+static bool print_args (bool ask, bool default_yes);
/* static void do_exec (void); */
static int xargs_do_exec (struct buildcmd_control *ctl, void *usercontext, int argc, char **argv);
static void exec_if_possible (void);
@@ -613,6 +619,10 @@ main (int argc, char **argv)
print_command = true;
break;
+ case INTERACTIVE_DEFAULT_YES_OPT:
+ interactive_default_yes = true;
+ break;
+
case 'r':
always_run_command = 0;
break;
@@ -1079,7 +1089,7 @@ read_string (void)
otherwise, return false. */
static bool
-print_args (bool ask)
+print_args (bool ask, bool default_yes)
{
size_t i;
@@ -1093,13 +1103,13 @@ print_args (bool ask)
{
static FILE *tty_stream;
int c, savec;
-
+ const char tty_dev[] = "/dev/tty";
if (!tty_stream)
{
- tty_stream = fopen_cloexec_for_read_only ("/dev/tty");
+ tty_stream = fopen_cloexec_for_read_only (tty_dev);
if (!tty_stream)
error (EXIT_FAILURE, errno,
- _("failed to open /dev/tty for reading"));
+ _("failed to open %s for reading"), tty_dev);
}
fputs ("?...", stderr);
if (fflush (stderr) != 0)
@@ -1109,8 +1119,8 @@ print_args (bool ask)
while (c != EOF && c != '\n')
c = getc (tty_stream);
if (EOF == c)
- error (EXIT_FAILURE, errno, _("Failed to read from stdin"));
- if (savec == 'y' || savec == 'Y')
+ error (EXIT_FAILURE, errno, _("Failed to read from %s"), tty_dev);
+ if (savec == 'y' || savec == 'Y' || (default_yes && savec == '\n'))
return true;
}
else
@@ -1233,10 +1243,10 @@ xargs_do_exec (struct buildcmd_control *ctl, void *usercontext, int argc, char *
}
}
- if (!query_before_executing || print_args (true))
+ if (!query_before_executing || print_args (true, interactive_default_yes))
{
if (!query_before_executing && print_command)
- print_args (false);
+ print_args (false, interactive_default_yes);
/* Before forking, reap any already-exited child. We do this so
that we don't leave unreaped children around while we build a
@@ -1686,6 +1696,7 @@ usage (int status)
HTL (_(" --show-limits show limits on command-line length\n"));
HTL (_(" -t, --verbose print commands before executing them\n"));
HTL (_(" -x, --exit exit if the size (see -s) is exceeded\n"));
+ HTL (_(" --interactive-default-yes assume return means 'y' with --interactive\n"));
HTL (_(" --help display this help and exit\n"));
HTL (_(" --version output version information and exit\n\n"));
--
2.1.4
