Date: Wed, 13 Feb 2002 16:16:34 +1100 From: Tim Robbins <tim@robbins.dropbear.id.au> To: freebsd-standards@FreeBSD.ORG Subject: xargs(1) -E, -p options and exit status Message-ID: <20020213161634.A4626@descent.robbins.dropbear.id.au>
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This patch corrects the exit status of xargs as well as adds the
P1003.1-2001 -E and -p options. I have not added -L and -I options because
jmallett is already working on those.
It's worth pointing out that the versions of xargs in -STABLE and -CURRENT
are NOT POSIX.2 compliant as they claim. Revision 1.7 to xargs.c totally
broke the documented 127 exit status by switching from vfork() to fork().
tim@descent$ echo 'hello' | xargs /no
xargs: /no: No such file or directory
tim@descent$ echo $?
1
Additionally, it would never exit 126 as required by P1003.2.
Tim
Index: xargs/xargs.1
===================================================================
RCS file: /home/ncvs/src/usr.bin/xargs/xargs.1,v
retrieving revision 1.15
diff -u -r1.15 xargs.1
--- xargs/xargs.1 2001/07/05 08:51:08 1.15
+++ xargs/xargs.1 2002/02/13 05:15:34
@@ -44,14 +44,14 @@
.Nd "construct argument list(s) and execute utility"
.Sh SYNOPSIS
.Nm
-.Op Fl 0
+.Op Fl 0pt
+.Op Fl E Ar eofstr
.Op Fl J Ar replstr
.Oo
.Fl n Ar number
.Op Fl x
.Oc
.Op Fl s Ar size
-.Op Fl t
.Op Ar utility Op Ar argument ...
.Sh DESCRIPTION
The
@@ -92,6 +92,10 @@
.Fl print0
function in
.Xr find 1 .
+.It Fl E Ar eofstr
+Use
+.Ar eofstr
+as a logical EOF marker.
.It Fl J Ar replstr
If this option is specified,
.Nm
@@ -142,6 +146,13 @@
The current default value for
.Ar number
is 5000.
+.It Fl p
+Echo each command to be executed and ask the user whether it should be
+executed.
+A response of
+.Ql y
+causes the command to be executed, any other response causes it to be
+skipped.
.It Fl s Ar size
Set the maximum number of bytes for the command line length provided to
.Ar utility .
@@ -184,15 +195,19 @@
.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.
-.Pp
+.Sh DIAGNOSTICS
The
.Nm
utility exits with a value of 0 if no error occurs.
If
+.Ar utility
+cannot be found,
+.Nm
+exits with a value of 127, otherwise if
.Ar utility
-cannot be invoked,
+cannot be executed,
.Nm
-exits with a value of 127.
+exits with a value of 126.
If any other error occurs,
.Nm
exits with a value of 1.
Index: xargs/xargs.c
===================================================================
RCS file: /home/ncvs/src/usr.bin/xargs/xargs.c,v
retrieving revision 1.11
diff -u -r1.11 xargs.c
--- xargs/xargs.c 2001/12/11 22:36:26 1.11
+++ xargs/xargs.c 2002/02/13 05:15:36
@@ -52,6 +52,7 @@
#include <sys/wait.h>
#include <err.h>
+#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -59,7 +60,7 @@
#include "pathnames.h"
-int tflag, rval;
+int pflag, tflag, rval;
int zflag;
void run __P((char **));
@@ -74,14 +75,16 @@
{
int ch;
char *p, *bbp, **bxp, *ebp, **exp, **xp;
- int cnt, jfound, indouble, insingle;
+ int cnt, jfound, indouble, insingle, foundeof;
int nargs, nflag, nline, xflag, wasquoted;
char **av, **avj, *argp, **ep, *replstr;
+ const char *eofstr;
long arg_max;
ep = env;
jfound = 0;
replstr = NULL; /* set if user requests -J */
+ eofstr = "";
/*
* POSIX.2 limits the exec line length to ARG_MAX - 2K. Running that
@@ -105,8 +108,11 @@
nline -= strlen(*ep++) + 1 + sizeof(*ep);
}
nflag = xflag = wasquoted = 0;
- while ((ch = getopt(argc, argv, "0J:n:s:tx")) != -1)
+ while ((ch = getopt(argc, argv, "0E:J:n:ps:tx")) != -1)
switch(ch) {
+ case 'E':
+ eofstr = optarg;
+ break;
case 'J':
replstr = optarg;
break;
@@ -115,6 +121,9 @@
if ((nargs = atoi(optarg)) <= 0)
errx(1, "illegal argument count");
break;
+ case 'p':
+ pflag = 1;
+ break;
case 's':
nline = atoi(optarg);
break;
@@ -216,8 +225,11 @@
errx(1, "unterminated quote");
arg2:
+ foundeof = *eofstr != '\0' &&
+ strcmp(argp, eofstr) == 0;
+
/* Do not make empty args unless they are quoted */
- if (argp != p || wasquoted) {
+ if ((argp != p || wasquoted) && !foundeof) {
*p++ = '\0';
*xp++ = argp;
}
@@ -227,7 +239,7 @@
* run the command. If xflag and max'd out on buffer
* but not on args, object.
*/
- if (xp == exp || p > ebp || ch == EOF) {
+ if (xp == exp || p > ebp || ch == EOF || foundeof) {
if (xflag && xp != exp && p > ebp)
errx(1, "insufficient space for arguments");
if (jfound) {
@@ -236,7 +248,7 @@
}
*xp = NULL;
run(av);
- if (ch == EOF)
+ if (ch == EOF || foundeof)
exit(rval);
p = bbp;
xp = bxp;
@@ -296,34 +308,51 @@
run(argv)
char **argv;
{
- volatile int noinvoke;
char **p;
+ FILE *ttyfp;
pid_t pid;
- int status;
+ int ch, status, sverrno;
- if (tflag) {
+ if (tflag || pflag) {
(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) {
+ if ((ttyfp = fopen("/dev/tty", "r")) != NULL) {
+ (void)fprintf(stderr, "?");
+ (void)fflush(stderr);
+ ch = getc(ttyfp);
+ fclose(ttyfp);
+ if (ch != 'y')
+ return;
+ }
+ } else {
+ (void)fprintf(stderr, "\n");
+ (void)fflush(stderr);
+ }
}
- noinvoke = 0;
switch(pid = fork()) {
case -1:
err(1, "fork");
case 0:
execvp(argv[0], argv);
+ sverrno = errno;
warn("%s", argv[0]);
- noinvoke = 1;
- _exit(1);
+ /*
+ * XXX Parent needs to know whether the utility couldn't be
+ * found, or if it was found but could not be invoked.
+ */
+ _exit(sverrno == ENOENT ? 254 : 253);
}
pid = waitpid(pid, &status, 0);
if (pid == -1)
err(1, "waitpid");
- /* If we couldn't invoke the utility, exit 127. */
- if (noinvoke)
+ /* Exit 127 if the utility could not be found */
+ if (WEXITSTATUS(status) == 254)
exit(127);
+ /* Exit 126 if the utility was found but not could be invoked */
+ if (WEXITSTATUS(status) == 253)
+ exit(126);
/* If utility signaled or exited with a value of 255, exit 1-125. */
if (WIFSIGNALED(status) || WEXITSTATUS(status) == 255)
exit(1);
@@ -335,7 +364,7 @@
usage()
{
fprintf(stderr,
- "usage: xargs [-0t] [-J replstr] [-n number [-x]] [-s size]\n"
- " [utility [argument ...]]\n");
+"usage: xargs [-0pt] [-E eofstr] [-J replstr] [-n number [-x]] [-s size]\n"
+" [utility [argument ...]]\n");
exit(1);
}
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