commit: f0ce444240d26044f870cb9a26f2d3c8cf38ce11
parent aab88c6c5d3ad3a69add4436100e8523b5552fd5
Author: Haelwenn (lanodan) Monnier <contact@hacktivis.me>
Date: Thu, 18 Apr 2024 03:34:07 +0200
cmd/nice: new
Diffstat:
5 files changed, 151 insertions(+), 3 deletions(-)
diff --git a/cmd/nice.1 b/cmd/nice.1
@@ -0,0 +1,57 @@
+.\" utils-std: Collection of commonly available Unix tools
+.\" Copyright 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
+.\" SPDX-License-Identifier: MPL-2.0
+.Dd 2024-04-18
+.Dt NICE 1
+.Os
+.Sh NAME
+.Nm nice
+.Nd invoke command with modified nice scheduling value
+.Sh SYNOPSIS
+.Nm
+.Op Fl n Ar increment
+.Ar command
+.Op Ar arguments ...
+.Sh DESCRIPTION
+.Nm
+runs
+.Ar command
+with a modified niceness, changing the scheduling of the process.
+.Pp
+As required by POSIX, if the user lacks the privileges to change the niceness a warning message is printed to stderr but the execution continues and
+.Ar command
+gets executed, without it's niceness changed.
+.Sh OPTIONS
+.Bl -tag -width Ds
+.It Fl n Ar increment
+Positive or negative integer used to adjust the niceness of the process. (default: 0)
+.El
+.Sh EXIT STATUS
+If
+.Ar command
+is invoked, the exit status of
+.Nm
+shall be the exit status of
+.Ar command ;
+Otherwise, the
+.Nm
+utility shall exit with one of the following values:
+.Bl -tag -width Ds
+.It 125
+An error occured within the
+.Nm
+utility.
+.It 126
+.Ar command
+was found but couldn't be invoked.
+.It 127
+.Ar command
+wasn't found.
+.El
+.Sh STANDARDS
+.Nm
+should be compliant with the
+.St -p1003.1-2008
+specification.
+.Sh AUTHORS
+.An Haelwenn (lanodan) Monnier Aq Mt contact+utils@hacktivis.me
diff --git a/cmd/nice.c b/cmd/nice.c
@@ -0,0 +1,91 @@
+// utils-std: Collection of commonly available Unix tools
+// SPDX-FileCopyrightText: 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
+// SPDX-License-Identifier: MPL-2.0
+
+#define _POSIX_C_SOURCE 200809L
+#define _XOPEN_SOURCE 700 // nice() is in XSI
+
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h> // fprintf
+#include <stdlib.h> // abort
+#include <string.h> // strerror
+#include <unistd.h> // getopt, nice
+
+static void
+usage()
+{
+ fprintf(stderr, "Usage: nice [-n increment] command [argument ...]\n");
+}
+
+int
+main(int argc, char *argv[])
+{
+ long incr = 0;
+
+ int c = -1;
+ while((c = getopt(argc, argv, ":n:")) != -1)
+ {
+ switch(c)
+ {
+ case 'n':
+ assert(errno == 0);
+ char *endptr = "";
+
+ incr = strtol(optarg, &endptr, 10);
+
+ if(*endptr != 0) errno = EINVAL;
+ if(errno != 0)
+ {
+ fprintf(
+ stderr, "nice: Error: Failed parsing '%s' as a number: %s\n", optarg, strerror(errno));
+ usage();
+ return 125;
+ }
+ break;
+ case ':':
+ fprintf(stderr, "nice: Error: Missing operand for option: '-%c'\n", optopt);
+ usage();
+ return 125;
+ case '?':
+ fprintf(stderr, "nice: Error: Unrecognised option: '-%c'\n", optopt);
+ usage();
+ return 125;
+ default:
+ abort();
+ }
+ }
+
+ argc -= optind;
+ argv += optind;
+
+ errno = 0;
+
+ if(nice((int)incr) == -1)
+ {
+ switch(errno)
+ {
+ case 0:
+ break;
+ case EPERM:
+ fprintf(stderr, "nice: Warning: Failed setting nice to %ld: %s\n", incr, strerror(errno));
+ errno = 0;
+ break;
+ default:
+ fprintf(stderr, "nice: Error: Failed setting nice to %ld: %s\n", incr, strerror(errno));
+ return 125;
+ }
+ }
+
+ assert(argv[0]);
+ assert(errno == 0);
+ /* flawfinder: ignore. No restrictions on commands is intended */
+ if(execvp(argv[0], argv) < 0)
+ {
+ fprintf(stderr, "nice: execvp(\"%s\", ...): %s\n", argv[0], strerror(errno));
+
+ return (errno == ENOENT) ? 127 : 126;
+ }
+
+ abort();
+}
diff --git a/coreutils.txt b/coreutils.txt
@@ -48,7 +48,7 @@ mkfifo: ?
mknod: Todo
mktemp: Todo
mv: Todo
-nice: Maybe
+nice: Done
nl: No, use sed
nohup: Done
nproc: ?
diff --git a/lsb_commands.txt b/lsb_commands.txt
@@ -86,7 +86,7 @@ mount: out of scope
msgfmt: out of scope
mv: Todo
newgrp: out of scope
-nice: Maybe
+nice: Done
nl: No, use sed
nohup: Done
od: Todo
diff --git a/posix_utilities.txt b/posix_utilities.txt
@@ -85,7 +85,7 @@ mkfifo
more: no?
mv
newgrp
-nice
+nice: done
nl
nm: no, toolchain
nohup: done
