sysctl: add -e: supress warnings about invalid key (Jeremy Kerr <jk@ozlabs.org>)

code shrink:

   text    data     bss     dec     hex filename
 775565     929    9100  785594   bfcba busybox_old
 775296     929    9100  785325   bfbad busybox_unstripped

2 files changed, 77 insertions, 102 deletions

diff --git a/include/usage.h b/include/usage.h
index d910e2bf6..0ae819a1a 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -3505,16 +3505,17 @@ USE_FEATURE_RUN_PARTS_FANCY("\n	-l	Prints names of all matching files even when
        "Configure kernel parameters at runtime" \
        "\n\nOptions:\n" \
        "        -n      Disable printing of key names\n" \
+       "        -e      Don't warn about unknown keys\n" \
        "        -w      Change sysctl setting\n" \
        "        -p FILE Load sysctl settings from FILE (default /etc/sysctl.conf)\n" \
        "        -a      Display all values\n" \
        "        -A      Display all values in table form"
 #define sysctl_example_usage \
-       "sysctl [-n] variable...\n" \
-       "sysctl [-n] -w variable=value...\n" \
-       "sysctl [-n] -a\n" \
-       "sysctl [-n] -p file     (default /etc/sysctl.conf)\n" \
-       "sysctl [-n] -A\n"
+       "sysctl [-n] [-e] variable...\n" \
+       "sysctl [-n] [-e] -w variable=value...\n" \
+       "sysctl [-n] [-e] -a\n" \
+       "sysctl [-n] [-e] -p file        (default /etc/sysctl.conf)\n" \
+       "sysctl [-n] [-e] -A\n"
 
 #define syslogd_trivial_usage \
        "[OPTION]..."
diff --git a/procps/sysctl.c b/procps/sysctl.c
index a12948017..3a0af02d2 100644
--- a/procps/sysctl.c
+++ b/procps/sysctl.c
@@ -16,24 +16,16 @@
 
 #include "libbb.h"
 
-/*
- *    Function Prototypes
- */
-static int sysctl_read_setting(const char *setting, int output);
-static int sysctl_write_setting(const char *setting, int output);
-static int sysctl_preload_file(const char *filename, int output);
-static int sysctl_display_all(const char *path, int output, int show_table);
+static int sysctl_read_setting(const char *setting);
+static int sysctl_write_setting(const char *setting);
+static int sysctl_display_all(const char *path);
+static int sysctl_preload_file_and_exit(const char *filename);
 
-/*
- *    Globals...
- */
 static const char ETC_SYSCTL_CONF[] ALIGN1 = "/etc/sysctl.conf";
 static const char PROC_SYS[] ALIGN1 = "/proc/sys/";
 enum { strlen_PROC_SYS = sizeof(PROC_SYS) - 1 };
 
 /* error messages */
-static const char ERR_UNKNOWN_PARAMETER[] ALIGN1 =
-        "error: unknown parameter '%s'";
 static const char ERR_MALFORMED_SETTING[] ALIGN1 =
         "error: malformed setting '%s'";
 static const char ERR_NO_EQUALS[] ALIGN1 =
@@ -46,8 +38,6 @@ static const char ERR_UNKNOWN_READING[] ALIGN1 =
         "error reading key '%s'";
 static const char ERR_PERMISSION_DENIED[] ALIGN1 =
         "error: permission denied on key '%s'";
-static const char ERR_PRELOAD_FILE[] ALIGN1 =
-        "error: cannot open preload file '%s'";
 static const char WARN_BAD_LINE[] ALIGN1 =
         "warning: %s(%d): invalid syntax, continuing";
 
@@ -57,66 +47,50 @@ static void dwrite_str(int fd, const char *buf)
         write(fd, buf, strlen(buf));
 }
 
-/*
- *    sysctl_main()...
- */
+enum {
+        FLAG_SHOW_KEYS       = 1 << 0,
+        FLAG_SHOW_KEY_ERRORS = 1 << 1,
+        FLAG_TABLE_FORMAT    = 1 << 2, /* not implemented */
+        FLAG_SHOW_ALL        = 1 << 3,
+        FLAG_PRELOAD_FILE    = 1 << 4,
+        FLAG_WRITE           = 1 << 5,
+};
+
 int sysctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int sysctl_main(int argc, char **argv)
 {
-        int retval = 0;
-        int output = 1;
-        int write_mode = 0;
-        int switches_allowed = 1;
-
-        if (argc < 2)
-                bb_show_usage();
-
-        argv++;
-
-        for (; *argv /*&& **argv*/; argv++) {
-                if (switches_allowed && **argv == '-') {        /* we have a switch */
-                        switch ((*argv)[1]) {
-                        case 'n':
-                                output = 0;
-                                break;
-                        case 'w':
-                                write_mode = 1;
-                                switches_allowed = 0;
-                                break;
-                        case 'p':
-                                argv++;
-                                return sysctl_preload_file(((*argv /*&& **argv*/) ? *argv : ETC_SYSCTL_CONF),
-                                                        output);
-                        case 'a':
-                        case 'A':
-                                return sysctl_display_all(PROC_SYS, output,
-                                                        ((*argv)[1] == 'A'));
-                        default:
-                                bb_error_msg(ERR_UNKNOWN_PARAMETER, *argv);
-                                /* fall through */
-                        //case 'h':
-                        //case '?':
-                                bb_show_usage();
-                        }
-                } else {
-                        switches_allowed = 0;
-                        if (write_mode)
-                                retval |= sysctl_write_setting(*argv, output);
-                        else
-                                sysctl_read_setting(*argv, output);
-                }
+        int retval;
+        int opt;
+
+        opt = getopt32(argv, "+neAapw"); /* '+' - stop on first non-option */
+        argv += optind;
+        opt ^= (FLAG_SHOW_KEYS | FLAG_SHOW_KEY_ERRORS);
+        option_mask32 ^= (FLAG_SHOW_KEYS | FLAG_SHOW_KEY_ERRORS);
+
+        if (opt & (FLAG_TABLE_FORMAT | FLAG_SHOW_ALL))
+                return sysctl_display_all(PROC_SYS);
+        if (opt & FLAG_PRELOAD_FILE)
+                return sysctl_preload_file_and_exit(*argv ? *argv : ETC_SYSCTL_CONF);
+
+        retval = 0;
+        while (*argv) {
+                if (opt & FLAG_WRITE)
+                        retval |= sysctl_write_setting(*argv);
+                else
+                        retval |= sysctl_read_setting(*argv);
+                argv++;
         }
+
         return retval;
 } /* end sysctl_main() */
 
 /*
- * sysctl_preload_file
  * preload the sysctl's from a conf file
  * - we parse the file and then reform it (strip out whitespace)
  */
 #define PRELOAD_BUF 256
 
-static int sysctl_preload_file(const char *filename, int output)
+static int sysctl_preload_file_and_exit(const char *filename)
 {
         int lineno;
         char oneline[PRELOAD_BUF];
@@ -124,10 +98,7 @@ static int sysctl_preload_file(const char *filename, int output)
         char *name, *value;
         FILE *fp;
 
-        fp = fopen(filename, "r");
-        if (fp == NULL) {
-                bb_error_msg_and_die(ERR_PRELOAD_FILE, filename);
-        }
+        fp = xfopen(filename, "r");
 
         lineno = 0;
         while (fgets(oneline, sizeof(oneline) - 1, fp)) {
@@ -163,35 +134,36 @@ static int sysctl_preload_file(const char *filename, int output)
 
                 /* safe because sizeof(oneline) == sizeof(buffer) */
                 sprintf(buffer, "%s=%s", name, value);
-                sysctl_write_setting(buffer, output);
+                sysctl_write_setting(buffer);
         }
-        fclose(fp);
+        if (ENABLE_FEATURE_CLEAN_UP)
+                fclose(fp);
         return 0;
-} /* end sysctl_preload_file() */
+} /* end sysctl_preload_file_and_exit() */
 
 /*
  *     Write a single sysctl setting
  */
-static int sysctl_write_setting(const char *setting, int output)
+static int sysctl_write_setting(const char *setting)
 {
-        int retval = 0;
+        int retval;
         const char *name;
         const char *value;
         const char *equals;
         char *tmpname, *outname, *cptr;
-        int fd = -1;
+        int fd;
 
         name = setting;
         equals = strchr(setting, '=');
         if (!equals) {
                 bb_error_msg(ERR_NO_EQUALS, setting);
-                return -1;
+                return EXIT_FAILURE;
         }
 
         value = equals + 1;     /* point to the value in name=value */
         if (name == equals || !*value) {
                 bb_error_msg(ERR_MALFORMED_SETTING, setting);
-                return -2;
+                return EXIT_FAILURE;
         }
 
         tmpname = xasprintf("%s%.*s", PROC_SYS, (int)(equals - name), name);
@@ -207,7 +179,8 @@ static int sysctl_write_setting(const char *setting, int output)
         if (fd < 0) {
                 switch (errno) {
                 case ENOENT:
-                        bb_error_msg(ERR_INVALID_KEY, outname);
+                        if (option_mask32 & FLAG_SHOW_KEY_ERRORS)
+                                bb_error_msg(ERR_INVALID_KEY, outname);
                         break;
                 case EACCES:
                         bb_perror_msg(ERR_PERMISSION_DENIED, outname);
@@ -216,16 +189,15 @@ static int sysctl_write_setting(const char *setting, int output)
                         bb_perror_msg(ERR_UNKNOWN_WRITING, outname);
                         break;
                 }
-                retval = -1;
+                retval = EXIT_FAILURE;
         } else {
                 dwrite_str(fd, value);
                 close(fd);
-                if (output) {
-                        dwrite_str(STDOUT_FILENO, outname);
-                        dwrite_str(STDOUT_FILENO, " = ");
+                if (option_mask32 & FLAG_SHOW_KEYS) {
+                        printf("%s = ", outname);
                 }
-                dwrite_str(STDOUT_FILENO, value);
-                dwrite_str(STDOUT_FILENO, "\n");
+                puts(value);
+                retval = EXIT_SUCCESS;
         }
 
         free(tmpname);
@@ -236,18 +208,19 @@ static int sysctl_write_setting(const char *setting, int output)
 /*
  *     Read a sysctl setting
  */
-static int sysctl_read_setting(const char *setting, int output)
+static int sysctl_read_setting(const char *name)
 {
-        int retval = 0;
+        int retval;
         char *tmpname, *outname, *cptr;
         char inbuf[1025];
-        const char *name;
         FILE *fp;
 
-        if (!*setting)
-                bb_error_msg(ERR_INVALID_KEY, setting);
+        if (!*name) {
+                if (option_mask32 & FLAG_SHOW_KEY_ERRORS)
+                        bb_error_msg(ERR_INVALID_KEY, name);
+                return -1;
+        }
 
-        name = setting;
         tmpname = concat_path_file(PROC_SYS, name);
         outname = xstrdup(tmpname + strlen_PROC_SYS);
 
@@ -260,7 +233,8 @@ static int sysctl_read_setting(const char *setting, int output)
         if (fp == NULL) {
                 switch (errno) {
                 case ENOENT:
-                        bb_error_msg(ERR_INVALID_KEY, outname);
+                        if (option_mask32 & FLAG_SHOW_KEY_ERRORS)
+                                bb_error_msg(ERR_INVALID_KEY, outname);
                         break;
                 case EACCES:
                         bb_error_msg(ERR_PERMISSION_DENIED, outname);
@@ -269,16 +243,16 @@ static int sysctl_read_setting(const char *setting, int output)
                         bb_perror_msg(ERR_UNKNOWN_READING, outname);
                         break;
                 }
-                retval = -1;
+                retval = EXIT_FAILURE;
         } else {
                 while (fgets(inbuf, sizeof(inbuf) - 1, fp)) {
-                        if (output) {
-                                dwrite_str(STDOUT_FILENO, outname);
-                                dwrite_str(STDOUT_FILENO, " = ");
+                        if (option_mask32 & FLAG_SHOW_KEYS) {
+                                printf("%s = ", outname);
                         }
-                        dwrite_str(STDOUT_FILENO, inbuf);
+                        fputs(inbuf, stdout);
                 }
                 fclose(fp);
+                retval = EXIT_SUCCESS;
         }
 
         free(tmpname);
@@ -289,7 +263,7 @@ static int sysctl_read_setting(const char *setting, int output)
 /*
  *     Display all the sysctl settings
  */
-static int sysctl_display_all(const char *path, int output, int show_table)
+static int sysctl_display_all(const char *path)
 {
         int retval = 0;
         DIR *dp;
@@ -299,18 +273,18 @@ static int sysctl_display_all(const char *path, int output, int show_table)
 
         dp = opendir(path);
         if (!dp) {
-                return -1;
+                return EXIT_FAILURE;
         }
         while ((de = readdir(dp)) != NULL) {
                 tmpdir = concat_subpath_file(path, de->d_name);
                 if (tmpdir == NULL)
-                        continue;
+                        continue; /* . or .. */
                 if (stat(tmpdir, &ts) != 0) {
                         bb_perror_msg(tmpdir);
                 } else if (S_ISDIR(ts.st_mode)) {
-                        sysctl_display_all(tmpdir, output, show_table);
+                        retval |= sysctl_display_all(tmpdir);
                 } else {
-                        retval |= sysctl_read_setting(tmpdir + strlen_PROC_SYS, output);
+                        retval |= sysctl_read_setting(tmpdir + strlen_PROC_SYS);
                 }
                 free(tmpdir);
         } /* end while */