[src/trunk]: src/usr.bin/xargs Implement XCU5 prompt mode (-p).

[kleink <kleink%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1e80f488b2ac
branches:  trunk
changeset: 479821:1e80f488b2ac
user:      kleink <kleink%NetBSD.org@localhost>
date:      Wed Dec 22 14:41:00 1999 +0000

description:
Implement XCU5 prompt mode (-p).

diffstat:

 usr.bin/xargs/xargs.1 |  20 +++++++++++++-
 usr.bin/xargs/xargs.c |  66 ++++++++++++++++++++++++++++++++++++++------------
 2 files changed, 68 insertions(+), 18 deletions(-)

diffs (191 lines):

diff -r aed18fea8ab3 -r 1e80f488b2ac usr.bin/xargs/xargs.1
--- a/usr.bin/xargs/xargs.1     Wed Dec 22 14:39:18 1999 +0000
+++ b/usr.bin/xargs/xargs.1     Wed Dec 22 14:41:00 1999 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: xargs.1,v 1.9 1999/01/12 00:07:20 lukem Exp $
+.\"    $NetBSD: xargs.1,v 1.10 1999/12/22 14:41:00 kleink Exp $
 .\"
 .\" Copyright (c) 1990, 1991, 1993
 .\"    The Regents of the University of California.  All rights reserved.
@@ -37,7 +37,7 @@
 .\"
 .\"    @(#)xargs.1     8.1 (Berkeley) 6/6/93
 .\"
-.Dd January 12, 1999
+.Dd December 21, 1999
 .Dt XARGS 1
 .Os
 .Sh NAME
@@ -46,6 +46,7 @@
 .Sh SYNOPSIS
 .Nm
 .Op Fl 0
+.Op Fl p
 .Op Fl t
 .Oo Op Fl x
 .Fl n Ar number
@@ -107,6 +108,16 @@
 The current default value for
 .Ar number
 is 5000.
+.It Fl p
+Prompt mode: immediately before each command execution the user is prompted
+whether to execute the command instance.  If an affirmative response is read
+from
+.Pa /dev/tty
+the command will be executed; otherwise this particular invocation will be
+skipped.
+This option implies the
+.Fl t
+option.
 .It Fl s Ar size
 Set the maximum number of bytes for the command line length provided to
 .Ar utility .
@@ -148,6 +159,11 @@
 .Ar utility
 cannot be invoked, an invocation of the utility is terminated by a signal
 or an invocation of the utility exits with a value of 255.
+.Sh FILES
+.Bl -tag -width /dev/tty -compact
+.It Pa /dev/tty
+used to read responses in prompt mode
+.El
 .Sh DIAGNOSTICS
 .Nm
 exits with one of the following values:
diff -r aed18fea8ab3 -r 1e80f488b2ac usr.bin/xargs/xargs.c
--- a/usr.bin/xargs/xargs.c     Wed Dec 22 14:39:18 1999 +0000
+++ b/usr.bin/xargs/xargs.c     Wed Dec 22 14:41:00 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: xargs.c,v 1.11 1998/12/20 15:06:53 christos Exp $      */
+/*     $NetBSD: xargs.c,v 1.12 1999/12/22 14:41:01 kleink Exp $        */
 
 /*-
  * Copyright (c) 1990, 1993
@@ -46,27 +46,32 @@
 #if 0
 static char sccsid[] = "@(#)xargs.c    8.1 (Berkeley) 6/6/93";
 #endif
-__RCSID("$NetBSD: xargs.c,v 1.11 1998/12/20 15:06:53 christos Exp $");
+__RCSID("$NetBSD: xargs.c,v 1.12 1999/12/22 14:41:01 kleink Exp $");
 #endif /* not lint */
 
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <err.h>
 #include <errno.h>
+#include <langinfo.h>
+#include <limits.h>
+#include <locale.h>
+#include <paths.h>
+#include <regex.h>
+#include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
-#include <limits.h>
-#include <locale.h>
-#include <signal.h>
-#include <err.h>
 #include "pathnames.h"
 
-int tflag, zflag, rval;
+static int pflag, tflag, zflag, rval;
+static FILE *promptfile;
+static regex_t yesexpr;
 
-void   run __P((char **));
-int    main __P((int, char **));
-void   usage __P((void));
+static void    run __P((char **));
+int            main __P((int, char **));
+static void    usage __P((void));
 
 int
 main(argc, argv)
@@ -96,7 +101,7 @@
        nargs = 5000;
        nline = ARG_MAX - 4 * 1024;
        nflag = xflag = 0;
-       while ((ch = getopt(argc, argv, "0n:s:tx")) != -1)
+       while ((ch = getopt(argc, argv, "0n:ps:tx")) != -1)
                switch(ch) {
                case '0':
                        zflag = 1;
@@ -106,6 +111,9 @@
                        if ((nargs = atoi(optarg)) <= 0)
                                errx(1, "illegal argument count");
                        break;
+               case 'p':
+                       pflag = tflag = 1;
+                       break;
                case 's':
                        nline = atoi(optarg);
                        break;
@@ -171,6 +179,20 @@
                err(1, "malloc");
        ebp = (argp = p = bbp) + nline - 1;
 
+       if (pflag) {
+               int error;
+
+               if ((promptfile = fopen(_PATH_TTY, "r")) == NULL)
+                       err(1, "prompt mode: cannot open input");
+               if ((error = regcomp(&yesexpr, nl_langinfo(YESEXPR), REG_NOSUB))
+                   != 0) {
+                       char msg[NL_TEXTMAX];
+
+                       (void)regerror(error, NULL, msg, sizeof (msg));
+                       err(1, "cannot compile yesexpr: %s", msg);
+               }
+       }
+
        for (insingle = indouble = 0;;)
                switch(ch = getchar()) {
                case EOF:
@@ -269,7 +291,7 @@
        /* NOTREACHED */
 }
 
-void
+static void
 run(argv)
        char **argv;
 {
@@ -282,8 +304,20 @@
                (void)fprintf(stderr, "%s", *argv);
                for (p = argv + 1; *p; ++p)
                        (void)fprintf(stderr, " %s", *p);
-               (void)fprintf(stderr, "\n");
-               (void)fflush(stderr);
+               if (pflag) {
+                       char buf[LINE_MAX + 1];
+
+                       (void)fprintf(stderr, "?...");
+                       fflush(stderr);
+                       if (fgets(buf, sizeof (buf), promptfile) == NULL) {
+                               rval = 1;
+                               return;
+                       }
+                       if (regexec(&yesexpr, buf, 0, NULL, 0) != 0)
+                               return;
+               } else {
+                       (void)fprintf(stderr, "\n");
+               }
        }
        noinvoke = 0;
        switch(pid = vfork()) {
@@ -331,10 +365,10 @@
        }
 }
 
-void
+static void
 usage()
 {
        (void)fprintf(stderr,
-"usage: xargs [-0t] [-n number [-x]] [-s size] [utility [argument ...]]\n");
+"usage: xargs [-0pt] [-n number [-x]] [-s size] [utility [argument ...]]\n");
        exit(1);
 }