add nproc

diff --git a/Makefile b/Makefile
index 8f1708271564380eeb73751888372be93e1b2de7..c2c1e70b4307fcaaf7b1ca538f337a579cd40111 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 include config.mk
 
-TARGETS = realpath
+TARGETS = realpath nproc
 SRC = $(TARGETS:=.c)
 BIN = $(TARGETS:=-install)
 UNI = $(TARGETS:=-uninstall)

diff --git a/nproc.1 b/nproc.1
new file mode 100644 (file)
index 0000000..2d25c8f
--- /dev/null
+++ b/nproc.1
@@ -0,0 +1,71 @@
+.\"-
+.\"  Copyright (c) 2023 Piotr Paweł Stefaniak
+.\"
+.\"  SPDX-License-Identifier: BSD-2-Clause
+.\"  Redistribution and use in source and binary forms, with
+.\"  or without modification, are permitted provided that the
+.\"  following conditions are met:
+.\" 
+.\"  1. Redistributions of source code must retain the above
+.\"     copyright notice, this list of conditions and the
+.\"     following disclaimer.
+.\"  2. Redistributions in binary form must reproduce the
+.\"     above copyright notice, this list of conditions and
+.\"     the following disclaimer in the documentation and/or
+.\"     other materials provided with the distribution.
+.\"  
+.\"  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+.\"  CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
+.\"  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+.\"  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+.\"  PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+.\"  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY
+.\"  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+.\"  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+.\"  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+.\"  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+.\"  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+.\"  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+.\"  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+.\"  USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+.\"  OF SUCH DAMAGE.
+.\" 
+.Dd April 2026
+.Dt NPROC 1
+.Os
+.Sh NAME
+.Nm nproc
+.Nd print the number of processors
+.Sh SYNOPSIS
+.Nm
+.Op Fl a
+.Op Fl i Ar #
+.Sh DESCRIPTION
+The
+.Nm
+utility is used to print the number of processors available to the
+current process, unless the
+.Fl a
+flag is specified.
+.Pp
+The available flags are:
+.Bl -tag -width ".Fl i Ar #"
+.It Fl a
+Count all processors available on the system.
+.It Fl i Ar #
+The result is decreased by
+.Ar # ,
+but never below 1.
+.El
+.Sh COMPATIBILITY
+This program is
+.Sy NOT
+compatible with nproc as found in GNU coreutils.
+.Sh SEE ALSO
+.Xr cpuset 1
+.Sh AUTHORS
+.An -nosplit
+.An Mateusz Guzik Aq Mt mjg@FreeBSD.org
+wrote the original program for FreeBSD and
+.An Piotr Paweł Stefaniak Aq Mt pstef@FreeBSD.org
+wrote the original of this page.

diff --git a/nproc.c b/nproc.c
new file mode 100644 (file)
index 0000000..921ce7c
--- /dev/null
+++ b/nproc.c
@@ -0,0 +1,109 @@
+/*-
+ * Copyright (c) 2023 Mateusz Guzik
+ *
+ * Redistribution and use in source and binary forms, with
+ * or without modification, are permitted provided that the
+ * following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above
+ *    copyright notice, this list of conditions and the
+ *    following disclaimer.
+ * 2. Redistributions in binary form must reproduce the
+ *    above copyright notice, this list of conditions and
+ *    the following disclaimer in the documentation and/or
+ *    other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+ * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ */
+#include <errno.h>
+#include <getopt.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#ifndef _SC_NPROCESSORS_CONF
+#error "_SC_NPROCESSORS_CONF not defined, system incompatible"
+#endif
+
+#ifndef _SC_NPROCESSORS_ONLN
+#error "_SC_NPROCESSORS_ONLN not defined, system incompatible"
+#endif
+
+static void
+usage(const char* progname)
+{
+       fprintf(stderr, "usage: %s [-a] [-i #]\n", progname);
+       exit(2);
+}
+
+int
+main(int argc, char *argv[])
+{
+       char *progname;
+       char *endptr;
+       int ch, all;
+       long ignore, cpus;
+
+       ignore = 0;
+       all = 0;
+       
+       progname = argv[0];
+       while ((ch = getopt(argc, argv, "ai:")) >= 0) {
+               switch (ch) {
+               case 'a':
+                       all = 1;
+                       break;
+               case 'i':
+                       ignore = strtol(optarg, &endptr, 10);
+                       if (ignore < 0 || *endptr || errno) {
+                               fprintf(stderr, "%s: bad ignore count: %s\n",
+                                       progname, optarg);
+                               exit(2);
+                       }
+                       break;
+               default:
+                       usage(progname);
+               }
+       }
+
+       argc -= optind;
+       argv += optind;
+
+       if (argc)
+               usage(progname);
+       
+       if (all)
+               cpus = sysconf(_SC_NPROCESSORS_CONF);
+       else
+               cpus = sysconf(_SC_NPROCESSORS_ONLN);
+
+       if (cpus < 0) {
+               fprintf(stderr, "%s: sysconf: %s", progname, strerror(errno));
+               exit(1);
+       }
+
+       if (ignore >= cpus)
+               cpus = 1;
+       else
+               cpus -= ignore;
+
+       printf("%li\n", cpus);
+
+       return 0;
+}