1 files changed, 242 insertions, 146 deletions

diff --git a/plugins/check_apt.c b/plugins/check_apt.c
index 1eda45dd..9ed5b6cf 100644
--- a/plugins/check_apt.c
+++ b/plugins/check_apt.c
@@ -29,92 +29,98 @@
  *
  *****************************************************************************/
 
+#include "perfdata.h"
 const char *progname = "check_apt";
 const char *copyright = "2006-2024";
 const char *email = "devel@monitoring-plugins.org";
 
+#include "states.h"
+#include "output.h"
 #include "common.h"
 #include "runcmd.h"
 #include "utils.h"
 #include "regex.h"
+#include "check_apt.d/config.h"
 
-/* some constants */
-typedef enum {
-        UPGRADE,
-        DIST_UPGRADE,
-        NO_UPGRADE
-} upgrade_type;
-
-/* Character for hidden input file option (for testing). */
-#define INPUT_FILE_OPT CHAR_MAX + 1
 /* the default opts can be overridden via the cmdline */
-#define UPGRADE_DEFAULT_OPTS "-o 'Debug::NoLocking=true' -s -qq"
-#define UPDATE_DEFAULT_OPTS  "-q"
+const char *UPGRADE_DEFAULT_OPTS = "-o 'Debug::NoLocking=true' -s -qq";
+const char *UPDATE_DEFAULT_OPTS = "-q";
+
 /* until i commit the configure.in patch which gets this, i'll define
  * it here as well */
 #ifndef PATH_TO_APTGET
 #       define PATH_TO_APTGET "/usr/bin/apt-get"
 #endif /* PATH_TO_APTGET */
+
 /* String found at the beginning of the apt output lines we're interested in */
-#define PKGINST_PREFIX "Inst "
+const char *PKGINST_PREFIX = "Inst ";
 /* the RE that catches security updates */
-#define SECURITY_RE "^[^\\(]*\\(.* (Debian-Security:|Ubuntu:[^/]*/[^-]*-security)"
+const char *SECURITY_RE = "^[^\\(]*\\(.* (Debian-Security:|Ubuntu:[^/]*/[^-]*-security)";
 
 /* some standard functions */
-static int process_arguments(int /*argc*/, char ** /*argv*/);
+typedef struct {
+        int errorcode;
+        check_apt_config config;
+} check_apt_config_wrapper;
+static check_apt_config_wrapper process_arguments(int /*argc*/, char ** /*argv*/);
 static void print_help(void);
 void print_usage(void);
 
 /* construct the appropriate apt-get cmdline */
-static char *construct_cmdline(upgrade_type u, const char *opts);
+static char *construct_cmdline(upgrade_type /*u*/, const char * /*opts*/);
+
 /* run an apt-get update */
-static int run_update(void);
+typedef struct {
+        mp_subcheck sc;
+        bool stderr_warning;
+        bool exec_warning;
+} run_update_result;
+static run_update_result run_update(char *update_opts);
 
 typedef struct {
         int errorcode;
-        int package_count;
-        int security_package_count;
+        size_t package_count;
+        size_t security_package_count;
         char **packages_list;
         char **secpackages_list;
+        bool exec_warning;
 } run_upgrade_result;
 
 /* run an apt-get upgrade */
-static run_upgrade_result run_upgrade(void);
+run_upgrade_result run_upgrade(upgrade_type upgrade, const char *do_include, const char *do_exclude,
+                                                           const char *do_critical, const char *upgrade_opts,
+                                                           const char *input_filename);
 
 /* add another clause to a regexp */
-static char *add_to_regexp(char *expr, const char *next);
+static char *add_to_regexp(char * /*expr*/, const char * /*next*/);
 /* extract package name from Inst line */
-static char *pkg_name(char *line);
+static char *pkg_name(char * /*line*/);
 /* string comparison function for qsort */
-static int cmpstringp(const void *p1, const void *p2);
+static int cmpstringp(const void * /*p1*/, const void * /*p2*/);
 
 /* configuration variables */
-static int verbose = 0;                /* -v */
-static bool list = false;              /* list packages available for upgrade */
-static bool do_update = false;         /* whether to call apt-get update */
-static bool only_critical = false;     /* whether to warn about non-critical updates */
-static upgrade_type upgrade = UPGRADE; /* which type of upgrade to do */
-static char *upgrade_opts = NULL;      /* options to override defaults for upgrade */
-static char *update_opts = NULL;       /* options to override defaults for update */
-static char *do_include = NULL;        /* regexp to only include certain packages */
-static char *do_exclude = NULL;        /* regexp to only exclude certain packages */
-static char *do_critical = NULL;       /* regexp specifying critical packages */
-static char *input_filename = NULL;    /* input filename for testing */
-/* number of packages available for upgrade to return WARNING status */
-static int packages_warning = 1;
+static int verbose = 0; /* -v */
 
 /* other global variables */
-static int stderr_warning = 0; /* if a cmd issued output on stderr */
-static int exec_warning = 0;   /* if a cmd exited non-zero */
+static bool stderr_warning = false; /* if a cmd issued output on stderr */
+static bool exec_warning = false;   /* if a cmd exited non-zero */
 
 int main(int argc, char **argv) {
         /* Parse extra opts if any */
         argv = np_extra_opts(&argc, argv, progname);
 
-        if (process_arguments(argc, argv) == ERROR) {
+        check_apt_config_wrapper tmp_config = process_arguments(argc, argv);
+
+        if (tmp_config.errorcode == ERROR) {
                 usage_va(_("Could not parse arguments"));
         }
 
+        const check_apt_config config = tmp_config.config;
+
+        if (config.output_format_is_set) {
+                mp_set_format(config.output_format);
+        }
+
         /* Set signal handling and alarm timeout */
         if (signal(SIGALRM, timeout_alarm_handler) == SIG_ERR) {
                 usage_va(_("Cannot catch SIGALRM"));
@@ -123,54 +129,91 @@ int main(int argc, char **argv) {
         /* handle timeouts gracefully... */
         alarm(timeout_interval);
 
-        int result = STATE_UNKNOWN;
+        mp_check overall = mp_check_init();
         /* if they want to run apt-get update first... */
-        if (do_update) {
-                result = run_update();
+        if (config.do_update) {
+                run_update_result update_result = run_update(config.update_opts);
+
+                mp_add_subcheck_to_check(&overall, update_result.sc);
         }
 
         /* apt-get upgrade */
-        run_upgrade_result upgrad_res = run_upgrade();
+        run_upgrade_result upgrad_res =
+                run_upgrade(config.upgrade, config.do_include, config.do_exclude, config.do_critical,
+                                        config.upgrade_opts, config.input_filename);
 
-        result = max_state(result, upgrad_res.errorcode);
-        int packages_available = upgrad_res.package_count;
-        int sec_count = upgrad_res.security_package_count;
+        mp_subcheck sc_run_upgrade = mp_subcheck_init();
+        if (upgrad_res.errorcode == OK) {
+                sc_run_upgrade = mp_set_subcheck_state(sc_run_upgrade, STATE_OK);
+        }
+        xasprintf(&sc_run_upgrade.output, "Executed apt upgrade (dry run)");
+
+        mp_add_subcheck_to_check(&overall, sc_run_upgrade);
+
+        size_t packages_available = upgrad_res.package_count;
+        size_t number_of_security_updates = upgrad_res.security_package_count;
         char **packages_list = upgrad_res.packages_list;
         char **secpackages_list = upgrad_res.secpackages_list;
 
-        if (sec_count > 0) {
-                result = max_state(result, STATE_CRITICAL);
-        } else if (packages_available >= packages_warning && only_critical == false) {
-                result = max_state(result, STATE_WARNING);
-        } else if (result > STATE_UNKNOWN) {
-                result = STATE_UNKNOWN;
+        mp_perfdata pd_security_updates = perfdata_init();
+        pd_security_updates.value = mp_create_pd_value(number_of_security_updates);
+        pd_security_updates.label = "critical_updates";
+
+        mp_subcheck sc_security_updates = mp_subcheck_init();
+        xasprintf(&sc_security_updates.output, "Security updates available: %zu",
+                          number_of_security_updates);
+        mp_add_perfdata_to_subcheck(&sc_security_updates, pd_security_updates);
+
+        if (number_of_security_updates > 0) {
+                sc_security_updates = mp_set_subcheck_state(sc_security_updates, STATE_CRITICAL);
+        } else {
+                sc_security_updates = mp_set_subcheck_state(sc_security_updates, STATE_OK);
         }
 
-        printf(_("APT %s: %d packages available for %s (%d critical updates). %s%s%s%s|available_upgrades=%d;;;0 critical_updates=%d;;;0\n"),
-                   state_text(result), packages_available, (upgrade == DIST_UPGRADE) ? "dist-upgrade" : "upgrade", sec_count,
-                   (stderr_warning) ? " warnings detected" : "", (stderr_warning && exec_warning) ? "," : "",
-                   (exec_warning) ? " errors detected" : "", (stderr_warning || exec_warning) ? "." : "", packages_available, sec_count);
+        mp_perfdata pd_other_updates = perfdata_init();
+        pd_other_updates.value = mp_create_pd_value(packages_available);
+        pd_other_updates.label = "available_upgrades";
 
-        if (list) {
-                qsort(secpackages_list, sec_count, sizeof(char *), cmpstringp);
-                qsort(packages_list, packages_available - sec_count, sizeof(char *), cmpstringp);
+        mp_subcheck sc_other_updates = mp_subcheck_init();
 
-                for (int i = 0; i < sec_count; i++) {
-                        printf("%s (security)\n", secpackages_list[i]);
+        xasprintf(&sc_other_updates.output, "Updates available: %zu", packages_available);
+        sc_other_updates = mp_set_subcheck_default_state(sc_other_updates, STATE_OK);
+        mp_add_perfdata_to_subcheck(&sc_other_updates, pd_other_updates);
+
+        if (packages_available >= config.packages_warning && !config.only_critical) {
+                sc_other_updates = mp_set_subcheck_state(sc_other_updates, STATE_WARNING);
+        }
+
+        if (config.list) {
+                qsort(secpackages_list, number_of_security_updates, sizeof(char *), cmpstringp);
+                qsort(packages_list, packages_available - number_of_security_updates, sizeof(char *),
+                          cmpstringp);
+
+                for (size_t i = 0; i < number_of_security_updates; i++) {
+                        xasprintf(&sc_security_updates.output, "%s\n%s (security)", sc_security_updates.output,
+                                          secpackages_list[i]);
                 }
 
-                if (only_critical == false) {
-                        for (int i = 0; i < packages_available - sec_count; i++) {
-                                printf("%s\n", packages_list[i]);
+                if (!config.only_critical) {
+                        for (size_t i = 0; i < packages_available - number_of_security_updates; i++) {
+                                xasprintf(&sc_other_updates.output, "%s\n%s", sc_other_updates.output,
+                                                  packages_list[i]);
                         }
                 }
         }
+        mp_add_subcheck_to_check(&overall, sc_security_updates);
+        mp_add_subcheck_to_check(&overall, sc_other_updates);
 
-        return result;
+        mp_exit(overall);
 }
 
 /* process command-line arguments */
-int process_arguments(int argc, char **argv) {
+check_apt_config_wrapper process_arguments(int argc, char **argv) {
+        enum {
+                /* Character for hidden input file option (for testing). */
+                INPUT_FILE_OPT = CHAR_MAX + 1,
+                output_format_index,
+        };
         static struct option longopts[] = {{"version", no_argument, 0, 'V'},
                                                                            {"help", no_argument, 0, 'h'},
                                                                            {"verbose", no_argument, 0, 'v'},
@@ -179,15 +222,21 @@ int process_arguments(int argc, char **argv) {
                                                                            {"upgrade", optional_argument, 0, 'U'},
                                                                            {"no-upgrade", no_argument, 0, 'n'},
                                                                            {"dist-upgrade", optional_argument, 0, 'd'},
-                                                                           {"list", no_argument, false, 'l'},
+                                                                           {"list", no_argument, 0, 'l'},
                                                                            {"include", required_argument, 0, 'i'},
                                                                            {"exclude", required_argument, 0, 'e'},
                                                                            {"critical", required_argument, 0, 'c'},
                                                                            {"only-critical", no_argument, 0, 'o'},
                                                                            {"input-file", required_argument, 0, INPUT_FILE_OPT},
                                                                            {"packages-warning", required_argument, 0, 'w'},
+                                                                           {"output-format", required_argument, 0, output_format_index},
                                                                            {0, 0, 0, 0}};
 
+        check_apt_config_wrapper result = {
+                .errorcode = OK,
+                .config = check_apt_config_init(),
+        };
+
         while (true) {
                 int option_char = getopt_long(argc, argv, "hVvt:u::U::d::nli:e:c:ow:", longopts, NULL);
 
@@ -209,96 +258,110 @@ int process_arguments(int argc, char **argv) {
                         timeout_interval = atoi(optarg);
                         break;
                 case 'd':
-                        upgrade = DIST_UPGRADE;
+                        result.config.upgrade = DIST_UPGRADE;
                         if (optarg != NULL) {
-                                upgrade_opts = strdup(optarg);
-                                if (upgrade_opts == NULL) {
+                                result.config.upgrade_opts = strdup(optarg);
+                                if (result.config.upgrade_opts == NULL) {
                                         die(STATE_UNKNOWN, "strdup failed");
                                 }
                         }
                         break;
                 case 'U':
-                        upgrade = UPGRADE;
+                        result.config.upgrade = UPGRADE;
                         if (optarg != NULL) {
-                                upgrade_opts = strdup(optarg);
-                                if (upgrade_opts == NULL) {
+                                result.config.upgrade_opts = strdup(optarg);
+                                if (result.config.upgrade_opts == NULL) {
                                         die(STATE_UNKNOWN, "strdup failed");
                                 }
                         }
                         break;
                 case 'n':
-                        upgrade = NO_UPGRADE;
+                        result.config.upgrade = NO_UPGRADE;
                         break;
                 case 'u':
-                        do_update = true;
+                        result.config.do_update = true;
                         if (optarg != NULL) {
-                                update_opts = strdup(optarg);
-                                if (update_opts == NULL) {
+                                result.config.update_opts = strdup(optarg);
+                                if (result.config.update_opts == NULL) {
                                         die(STATE_UNKNOWN, "strdup failed");
                                 }
                         }
                         break;
                 case 'l':
-                        list = true;
+                        result.config.list = true;
                         break;
                 case 'i':
-                        do_include = add_to_regexp(do_include, optarg);
+                        result.config.do_include = add_to_regexp(result.config.do_include, optarg);
                         break;
                 case 'e':
-                        do_exclude = add_to_regexp(do_exclude, optarg);
+                        result.config.do_exclude = add_to_regexp(result.config.do_exclude, optarg);
                         break;
                 case 'c':
-                        do_critical = add_to_regexp(do_critical, optarg);
+                        result.config.do_critical = add_to_regexp(result.config.do_critical, optarg);
                         break;
                 case 'o':
-                        only_critical = true;
+                        result.config.only_critical = true;
                         break;
                 case INPUT_FILE_OPT:
-                        input_filename = optarg;
+                        result.config.input_filename = optarg;
                         break;
                 case 'w':
-                        packages_warning = atoi(optarg);
+                        result.config.packages_warning = atoi(optarg);
+                        break;
+                case output_format_index: {
+                        parsed_output_format parser = mp_parse_output_format(optarg);
+                        if (!parser.parsing_success) {
+                                // TODO List all available formats here, maybe add anothoer usage function
+                                printf("Invalid output format: %s\n", optarg);
+                                exit(STATE_UNKNOWN);
+                        }
+
+                        result.config.output_format_is_set = true;
+                        result.config.output_format = parser.output_format;
                         break;
+                }
                 default:
                         /* print short usage statement if args not parsable */
                         usage5();
                 }
         }
 
-        return OK;
+        return result;
 }
 
 /* run an apt-get upgrade */
-run_upgrade_result run_upgrade(void) {
-        regex_t ereg;
+run_upgrade_result run_upgrade(const upgrade_type upgrade, const char *do_include,
+                                                           const char *do_exclude, const char *do_critical,
+                                                           const char *upgrade_opts, const char *input_filename) {
+        regex_t exclude_regex;
         /* initialize ereg as it is possible it is printed while uninitialized */
-        memset(&ereg, '\0', sizeof(ereg.buffer));
+        memset(&exclude_regex, '\0', sizeof(exclude_regex.buffer));
 
         run_upgrade_result result = {
-                .errorcode = STATE_UNKNOWN,
+                .errorcode = OK,
         };
 
         if (upgrade == NO_UPGRADE) {
-                result.errorcode = STATE_OK;
+                result.errorcode = OK;
                 return result;
         }
 
         int regres = 0;
-        regex_t ireg;
+        regex_t include_regex;
         char rerrbuf[64];
         /* compile the regexps */
         if (do_include != NULL) {
-                regres = regcomp(&ireg, do_include, REG_EXTENDED);
+                regres = regcomp(&include_regex, do_include, REG_EXTENDED);
                 if (regres != 0) {
-                        regerror(regres, &ireg, rerrbuf, 64);
+                        regerror(regres, &include_regex, rerrbuf, 64);
                         die(STATE_UNKNOWN, _("%s: Error compiling regexp: %s"), progname, rerrbuf);
                 }
         }
 
         if (do_exclude != NULL) {
-                regres = regcomp(&ereg, do_exclude, REG_EXTENDED);
+                regres = regcomp(&exclude_regex, do_exclude, REG_EXTENDED);
                 if (regres != 0) {
-                        regerror(regres, &ereg, rerrbuf, 64);
+                        regerror(regres, &exclude_regex, rerrbuf, 64);
                         die(STATE_UNKNOWN, _("%s: Error compiling regexp: %s"), progname, rerrbuf);
                 }
         }
@@ -307,12 +370,12 @@ run_upgrade_result run_upgrade(void) {
         const char *crit_ptr = (do_critical != NULL) ? do_critical : SECURITY_RE;
         regres = regcomp(&sreg, crit_ptr, REG_EXTENDED);
         if (regres != 0) {
-                regerror(regres, &ereg, rerrbuf, 64);
+                regerror(regres, &exclude_regex, rerrbuf, 64);
                 die(STATE_UNKNOWN, _("%s: Error compiling regexp: %s"), progname, rerrbuf);
         }
 
-        struct output chld_out;
-        struct output chld_err;
+        output chld_out;
+        output chld_err;
         char *cmdline = NULL;
         cmdline = construct_cmdline(upgrade, upgrade_opts);
         if (input_filename != NULL) {
@@ -323,16 +386,15 @@ run_upgrade_result run_upgrade(void) {
                 result.errorcode = np_runcmd(cmdline, &chld_out, &chld_err, 0);
         }
 
-        /* apt-get upgrade only changes exit status if there is an
-         * internal error when run in dry-run mode.  therefore we will
-         * treat such an error as UNKNOWN */
-        if (result.errorcode != STATE_OK) {
-                exec_warning = 1;
-                result.errorcode = STATE_UNKNOWN;
-                fprintf(stderr, _("'%s' exited with non-zero status.\n"), cmdline);
+        // apt-get upgrade only changes exit status if there is an
+        // internal error when run in dry-run mode.
+        if (result.errorcode != 0) {
+                result.exec_warning = true;
+                result.errorcode = ERROR;
+                // fprintf(stderr, _("'%s' exited with non-zero status.\n"), cmdline);
         }
 
-  char **pkglist = malloc(sizeof(char *) * chld_out.lines);
+        char **pkglist = malloc(sizeof(char *) * chld_out.lines);
         if (!pkglist) {
                 die(STATE_UNKNOWN, "malloc failed!\n");
         }
@@ -350,27 +412,31 @@ run_upgrade_result run_upgrade(void) {
          * we may need to switch to the --print-uris output format,
          * in which case the logic here will slightly change.
          */
-        int package_counter = 0;
-        int security_package_counter = 0;
+        size_t package_counter = 0;
+        size_t security_package_counter = 0;
         for (size_t i = 0; i < chld_out.lines; i++) {
                 if (verbose) {
                         printf("%s\n", chld_out.line[i]);
                 }
+
                 /* if it is a package we care about */
                 if (strncmp(PKGINST_PREFIX, chld_out.line[i], strlen(PKGINST_PREFIX)) == 0 &&
-                        (do_include == NULL || regexec(&ireg, chld_out.line[i], 0, NULL, 0) == 0)) {
+                        (do_include == NULL || regexec(&include_regex, chld_out.line[i], 0, NULL, 0) == 0)) {
                         /* if we're not excluding, or it's not in the
                          * list of stuff to exclude */
-                        if (do_exclude == NULL || regexec(&ereg, chld_out.line[i], 0, NULL, 0) != 0) {
+                        if (do_exclude == NULL || regexec(&exclude_regex, chld_out.line[i], 0, NULL, 0) != 0) {
                                 package_counter++;
                                 if (regexec(&sreg, chld_out.line[i], 0, NULL, 0) == 0) {
                                         security_package_counter++;
+
                                         if (verbose) {
                                                 printf("*");
                                         }
+
                                         (secpkglist)[security_package_counter - 1] = pkg_name(chld_out.line[i]);
                                 } else {
-                                        (pkglist)[package_counter - security_package_counter - 1] = pkg_name(chld_out.line[i]);
+                                        (pkglist)[package_counter - security_package_counter - 1] =
+                                                pkg_name(chld_out.line[i]);
                                 }
                                 if (verbose) {
                                         printf("*%s\n", chld_out.line[i]);
@@ -378,6 +444,7 @@ run_upgrade_result run_upgrade(void) {
                         }
                 }
         }
+
         result.package_count = package_counter;
         result.security_package_count = security_package_counter;
         result.packages_list = pkglist;
@@ -385,42 +452,56 @@ run_upgrade_result run_upgrade(void) {
 
         /* If we get anything on stderr, at least set warning */
         if (input_filename == NULL && chld_err.buflen) {
-                stderr_warning = 1;
-                result.errorcode = max_state(result.errorcode, STATE_WARNING);
+                stderr_warning = true;
+                result.errorcode = ERROR;
+
                 if (verbose) {
                         for (size_t i = 0; i < chld_err.lines; i++) {
                                 fprintf(stderr, "%s\n", chld_err.line[i]);
                         }
                 }
         }
+
         if (do_include != NULL) {
-                regfree(&ireg);
+                regfree(&include_regex);
         }
+
         regfree(&sreg);
+
         if (do_exclude != NULL) {
-                regfree(&ereg);
+                regfree(&exclude_regex);
         }
+
         free(cmdline);
+
         return result;
 }
 
 /* run an apt-get update (needs root) */
-int run_update(void) {
-        int result = STATE_UNKNOWN;
+run_update_result run_update(char *update_opts) {
         char *cmdline;
         /* run the update */
         cmdline = construct_cmdline(NO_UPGRADE, update_opts);
 
-        struct output chld_out;
-        struct output chld_err;
-        result = np_runcmd(cmdline, &chld_out, &chld_err, 0);
+        run_update_result result = {
+                .exec_warning = false,
+                .stderr_warning = false,
+                .sc = mp_subcheck_init(),
+        };
+
+        result.sc = mp_set_subcheck_default_state(result.sc, STATE_OK);
+        xasprintf(&result.sc.output, "executing '%s' first", cmdline);
+
+        output chld_out;
+        output chld_err;
+        int cmd_error = np_runcmd(cmdline, &chld_out, &chld_err, 0);
         /* apt-get update changes exit status if it can't fetch packages.
          * since we were explicitly asked to do so, this is treated as
          * a critical error. */
-        if (result != 0) {
-                exec_warning = 1;
-                result = STATE_CRITICAL;
-                fprintf(stderr, _("'%s' exited with non-zero status.\n"), cmdline);
+        if (cmd_error != 0) {
+                exec_warning = true;
+                result.sc = mp_set_subcheck_state(result.sc, STATE_CRITICAL);
+                xasprintf(&result.sc.output, _("'%s' exited with non-zero status.\n"), cmdline);
         }
 
         if (verbose) {
@@ -431,22 +512,25 @@ int run_update(void) {
 
         /* If we get anything on stderr, at least set warning */
         if (chld_err.buflen) {
-                stderr_warning = 1;
-                result = max_state(result, STATE_WARNING);
+                stderr_warning = true;
+                result.sc = mp_set_subcheck_state(
+                        result.sc, max_state(mp_compute_subcheck_state(result.sc), STATE_WARNING));
                 if (verbose) {
                         for (size_t i = 0; i < chld_err.lines; i++) {
                                 fprintf(stderr, "%s\n", chld_err.line[i]);
                         }
                 }
         }
+
         free(cmdline);
+
         return result;
 }
 
 char *pkg_name(char *line) {
         char *start = line + strlen(PKGINST_PREFIX);
 
-        int len = strlen(start);
+        size_t len = strlen(start);
 
         char *space = index(start, ' ');
         if (space != NULL) {
@@ -464,35 +548,37 @@ char *pkg_name(char *line) {
         return pkg;
 }
 
-int cmpstringp(const void *p1, const void *p2) { return strcmp(*(char *const *)p1, *(char *const *)p2); }
+int cmpstringp(const void *left_string, const void *right_string) {
+        return strcmp(*(char *const *)left_string, *(char *const *)right_string);
+}
 
 char *add_to_regexp(char *expr, const char *next) {
-        char *re = NULL;
+        char *regex_string = NULL;
 
         if (expr == NULL) {
-                re = malloc(sizeof(char) * (strlen("()") + strlen(next) + 1));
-                if (!re) {
+                regex_string = malloc(sizeof(char) * (strlen("()") + strlen(next) + 1));
+                if (!regex_string) {
                         die(STATE_UNKNOWN, "malloc failed!\n");
                 }
-                sprintf(re, "(%s)", next);
+                sprintf(regex_string, "(%s)", next);
         } else {
                 /* resize it, adding an extra char for the new '|' separator */
-                re = realloc(expr, sizeof(char) * (strlen(expr) + 1 + strlen(next) + 1));
-                if (!re) {
+                regex_string = realloc(expr, sizeof(char) * (strlen(expr) + 1 + strlen(next) + 1));
+                if (!regex_string) {
                         die(STATE_UNKNOWN, "realloc failed!\n");
                 }
                 /* append it starting at ')' in the old re */
-                sprintf((char *)(re + strlen(re) - 1), "|%s)", next);
+                sprintf((char *)(regex_string + strlen(regex_string) - 1), "|%s)", next);
         }
 
-        return re;
+        return regex_string;
 }
 
-char *construct_cmdline(upgrade_type u, const char *opts) {
+char *construct_cmdline(upgrade_type upgrade, const char *opts) {
         const char *opts_ptr = NULL;
         const char *aptcmd = NULL;
 
-        switch (u) {
+        switch (upgrade) {
         case UPGRADE:
                 if (opts == NULL) {
                         opts_ptr = UPGRADE_DEFAULT_OPTS;
@@ -519,7 +605,7 @@ char *construct_cmdline(upgrade_type u, const char *opts) {
                 break;
         }
 
-        int len = 0;
+        size_t len = 0;
         len += strlen(PATH_TO_APTGET) + 1; /* "/usr/bin/apt-get " */
         len += strlen(opts_ptr) + 1;       /* "opts " */
         len += strlen(aptcmd) + 1;         /* "upgrade\0" */
@@ -557,7 +643,8 @@ void print_help(void) {
         printf("    %s\n", _("List packages available for upgrade.  Packages are printed sorted by"));
         printf("    %s\n", _("name with security packages listed first."));
         printf(" %s\n", "-i, --include=REGEXP");
-        printf("    %s\n", _("Include only packages matching REGEXP.  Can be specified multiple times"));
+        printf("    %s\n",
+                   _("Include only packages matching REGEXP.  Can be specified multiple times"));
         printf("    %s\n", _("the values will be combined together.  Any packages matching this list"));
         printf("    %s\n", _("cause the plugin to return WARNING status.  Others will be ignored."));
         printf("    %s\n", _("Default is to include all packages."));
@@ -566,7 +653,8 @@ void print_help(void) {
         printf("    %s\n", _("otherwise be included.  Can be specified multiple times; the values"));
         printf("    %s\n", _("will be combined together.  Default is to exclude no packages."));
         printf(" %s\n", "-c, --critical=REGEXP");
-        printf("    %s\n", _("If the full package information of any of the upgradable packages match"));
+        printf("    %s\n",
+                   _("If the full package information of any of the upgradable packages match"));
         printf("    %s\n", _("this REGEXP, the plugin will return CRITICAL status.  Can be specified"));
         printf("    %s\n", _("multiple times like above.  Default is a regexp matching security"));
         printf("    %s\n", _("upgrades for Debian and Ubuntu:"));
@@ -575,15 +663,21 @@ void print_help(void) {
         printf("    %s\n", _("information is compared against the critical list."));
         printf(" %s\n", "-o, --only-critical");
         printf("    %s\n", _("Only warn about upgrades matching the critical list.  The total number"));
-        printf("    %s\n", _("of upgrades will be printed, but any non-critical upgrades will not cause"));
+        printf("    %s\n",
+                   _("of upgrades will be printed, but any non-critical upgrades will not cause"));
         printf("    %s\n", _("the plugin to return WARNING status."));
         printf(" %s\n", "-w, --packages-warning");
-        printf("    %s\n", _("Minimum number of packages available for upgrade to return WARNING status."));
+        printf("    %s\n",
+                   _("Minimum number of packages available for upgrade to return WARNING status."));
         printf("    %s\n\n", _("Default is 1 package."));
 
-        printf("%s\n\n", _("The following options require root privileges and should be used with care:"));
+        printf(UT_OUTPUT_FORMAT);
+
+        printf("%s\n\n",
+                   _("The following options require root privileges and should be used with care:"));
         printf(" %s\n", "-u, --update=OPTS");
-        printf("    %s\n", _("First perform an 'apt-get update'.  An optional OPTS parameter overrides"));
+        printf("    %s\n",
+                   _("First perform an 'apt-get update'.  An optional OPTS parameter overrides"));
         printf("    %s\n", _("the default options.  Note: you may also need to adjust the global"));
         printf("    %s\n", _("timeout (with -t) to prevent the plugin from timing out if apt-get"));
         printf("    %s\n", _("upgrade is expected to take longer than the default timeout."));
@@ -592,8 +686,10 @@ void print_help(void) {
         printf("    %s\n", _("apt-get will be run with these command line options instead of the"));
         printf("    %s", _("default "));
         printf("(%s).\n", UPGRADE_DEFAULT_OPTS);
-        printf("    %s\n", _("Note that you may be required to have root privileges if you do not use"));
-        printf("    %s\n", _("the default options, which will only run a simulation and NOT perform the upgrade"));
+        printf("    %s\n",
+                   _("Note that you may be required to have root privileges if you do not use"));
+        printf("    %s\n",
+                   _("the default options, which will only run a simulation and NOT perform the upgrade"));
         printf(" %s\n", "-d, --dist-upgrade=OPTS");
         printf("    %s\n", _("Perform a dist-upgrade instead of normal upgrade. Like with -U OPTS"));
         printf("    %s\n", _("can be provided to override the default options."));