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 */