sys-utils: cleanup license lines, add SPDX

[thirdparty/util-linux.git] / sys-utils / renice.c

diff --git a/sys-utils/renice.c b/sys-utils/renice.c
index ab23444aa8ba191d99fa67aa3baf6cc832b9575a..a8cf7411396828838c3dac9c03c9cd6e00259df0 100644 (file)
--- a/sys-utils/renice.c
+++ b/sys-utils/renice.c
@@ -1,4 +1,6 @@
 /*
+ * SPDX-License-Identifier: BSD-4-Clause-UC
+ *
  * Copyright (c) 1983, 1989, 1993
  *     The Regents of the University of California.  All rights reserved.
  *
@@ -59,22 +61,27 @@ static void __attribute__((__noreturn__)) usage(void)
        FILE *out = stdout;
        fputs(USAGE_HEADER, out);
        fprintf(out,
-             _(" %1$s [-n] <priority> [-p|--pid] <pid>...\n"
-               " %1$s [-n] <priority>  -g|--pgrp <pgid>...\n"
-               " %1$s [-n] <priority>  -u|--user <user>...\n"),
+             _(" %1$s [-n|--priority|--relative] <priority> [-p|--pid] <pid>...\n"
+               " %1$s [-n|--priority|--relative] <priority>  -g|--pgrp <pgid>...\n"
+               " %1$s [-n|--priority|--relative] <priority>  -u|--user <user>...\n"),
                program_invocation_short_name);
 
        fputs(USAGE_SEPARATOR, out);
        fputs(_("Alter the priority of running processes.\n"), out);
 
        fputs(USAGE_OPTIONS, out);
-       fputs(_(" -n, --priority <num>   specify the nice value\n"), out);
-       fputs(_(" -p, --pid <id>         interpret argument as process ID (default)\n"), out);
-       fputs(_(" -g, --pgrp <id>        interpret argument as process group ID\n"), out);
-       fputs(_(" -u, --user <name>|<id> interpret argument as username or user ID\n"), out);
+       fputs(_(" -n <num>               specify the nice value\n"), out);
+       fputs(_("                          If POSIXLY_CORRECT flag is set in environment\n"), out);
+       fputs(_("                          then the priority is 'relative' to current\n"), out);
+       fputs(_("                          process priority. Otherwise it is 'absolute'.\n"), out);
+       fputs(_(" --priority <num>       specify the 'absolute' nice value\n"), out);
+       fputs(_(" --relative <num>       specify the 'relative' nice value\n"), out);
+       fputs(_(" -p, --pid              interpret arguments as process ID (default)\n"), out);
+       fputs(_(" -g, --pgrp             interpret arguments as process group ID\n"), out);
+       fputs(_(" -u, --user             interpret arguments as username or user ID\n"), out);
        fputs(USAGE_SEPARATOR, out);
-       printf(USAGE_HELP_OPTIONS(24));
-       printf(USAGE_MAN_TAIL("renice(1)"));
+       fprintf(out, USAGE_HELP_OPTIONS(24));
+       fprintf(out, USAGE_MAN_TAIL("renice(1)"));
        exit(EXIT_SUCCESS);
 }
 
@@ -89,13 +96,19 @@ static int getprio(const int which, const int who, int *prio)
        return 0;
 }
 
-static int donice(const int which, const int who, const int prio)
+static int donice(const int which, const int who, const int prio, const int relative)
 {
        int oldprio, newprio;
 
        if (getprio(which, who, &oldprio) != 0)
                return 1;
-       if (setpriority(which, who, prio) < 0) {
+
+       newprio = prio; // if not relative, set absolute priority
+
+       if (relative)
+               newprio = oldprio + prio;
+
+       if (setpriority(which, who, newprio) < 0) {
                warn(_("failed to set priority for %d (%s)"), who, idtype[which]);
                return 1;
        }
@@ -114,6 +127,7 @@ int main(int argc, char **argv)
 {
        int which = PRIO_PROCESS;
        int who = 0, prio, errs = 0;
+       int relative = 0;
        char *endptr = NULL;
 
        setlocale(LC_ALL, "");
@@ -135,9 +149,28 @@ int main(int argc, char **argv)
                        print_version(EXIT_SUCCESS);
        }
 
-       if (*argv && (strcmp(*argv, "-n") == 0 || strcmp(*argv, "--priority") == 0)) {
-               argc--;
-               argv++;
+       if (*argv)
+       {
+               if (strcmp(*argv, "-n") == 0)
+               {
+                       // Fully conform to posix only if POSIXLY_CORRECT is
+                       // set in the environment. If not, use the absolute
+                       // value as it's been used (incorrectly) since 2009
+                       relative = getenv("POSIXLY_CORRECT") == NULL ? 0 : 1;
+                       argc--;
+                       argv++;
+               }
+               else if (strcmp(*argv, "--relative") == 0)
+               {
+                       relative = 1;
+                       argc--;
+                       argv++;
+               }
+               else if (strcmp(*argv, "--priority") == 0) {
+                       relative = 0;
+                       argc--;
+                       argv++;
+               }
        }
 
        if (argc < 2 || !*argv) {
@@ -188,7 +221,7 @@ int main(int argc, char **argv)
                                continue;
                        }
                }
-               errs |= donice(which, who, prio);
+               errs |= donice(which, who, prio, relative);
        }
        return errs != 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 }