sysctl: recognize ";comment" and "<whitespace>#comment" lines

function                                             old     new   delta
config_read                                          639     699     +60

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

3 files changed, 19 insertions, 5 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 6077f64c9..51e8f27a5 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1403,6 +1403,11 @@ enum {
         // keep a copy of current line
         PARSE_KEEP_COPY = 0x00200000 * ENABLE_FEATURE_CROND_D,
         PARSE_EOL_COMMENTS = 0x00400000, // comments are recognized even if they aren't the first char
+        PARSE_ALT_COMMENTS = 0x00800000, // delim[0] and delim[1] are two different allowed comment chars
+        // (so far, delim[0] will only work as comment char for full-line comment)
+        // (IOW: it works as if PARSE_EOL_COMMENTS is not set. sysctl applet is okay with this)
+        PARSE_WS_COMMENTS  = 0x01000000, // comments are recognized even if there is whitespace before
+        // ("line start><space><tab><space>#comment" is also comment, not only "line start>#comment")
         // NORMAL is:
         // * remove leading and trailing delimiters and collapse
         //   multiple delimiters into one
diff --git a/libbb/parse_config.c b/libbb/parse_config.c
index da7482c6d..eaf69d97f 100644
--- a/libbb/parse_config.c
+++ b/libbb/parse_config.c
@@ -161,13 +161,18 @@ mintokens > 0 make config_read() print error message if less than mintokens
 #undef config_read
 int FAST_FUNC config_read(parser_t *parser, char **tokens, unsigned flags, const char *delims)
 {
-        char *line;
+        char *line, *p;
         int ntokens, mintokens;
         int t;
+        char alt_comment_ch;
 
         if (!parser)
                 return 0;
 
+        alt_comment_ch = '\0';
+        if (flags & PARSE_ALT_COMMENTS)
+                alt_comment_ch = *delims++;
+
         ntokens = (uint8_t)flags;
         mintokens = (uint8_t)(flags >> 8);
 
@@ -184,7 +189,10 @@ int FAST_FUNC config_read(parser_t *parser, char **tokens, unsigned flags, const
         if (flags & PARSE_TRIM)
                 line += strspn(line, delims + 1);
 
-        if (line[0] == '\0' || line[0] == delims[0])
+        p = line;
+        if (flags & PARSE_WS_COMMENTS)
+                p = skip_whitespace(p);
+        if (p[0] == '\0' || p[0] == delims[0] || p[0] == alt_comment_ch)
                 goto again;
 
         if (flags & PARSE_KEEP_COPY) {
diff --git a/procps/sysctl.c b/procps/sysctl.c
index ef1a1b99f..a42a91247 100644
--- a/procps/sysctl.c
+++ b/procps/sysctl.c
@@ -247,15 +247,16 @@ static int sysctl_handle_preload_file(const char *filename)
         /* Must do it _after_ config_open(): */
         xchdir("/proc/sys");
 
-//TODO: ';' is comment char too
-//TODO: <space><tab><space>#comment is also comment, not strictly 1st char only
         parse_flags = 0;
         parse_flags &= ~PARSE_COLLAPSE;   // NO (var==val is not var=val) - treat consecutive delimiters as one
         parse_flags &= ~PARSE_TRIM;       // NO - trim leading and trailing delimiters
         parse_flags |= PARSE_GREEDY;      // YES - last token takes entire remainder of the line
         parse_flags &= ~PARSE_MIN_DIE;    // NO - die if < min tokens found
         parse_flags &= ~PARSE_EOL_COMMENTS; // NO (only first char) - comments are recognized even if not first char
-        while (config_read(parser, token, 2, 2, "#=", parse_flags)) {
+        parse_flags |= PARSE_ALT_COMMENTS;// YES - two comment chars: ';' and '#'
+        /* <space><tab><space>#comment is also comment, not strictly 1st char only */
+        parse_flags |= PARSE_WS_COMMENTS; // YES - comments are recognized even if there is whitespace before
+        while (config_read(parser, token, 2, 2, ";#=", parse_flags)) {
                 char *tp;
 
                 trim(token[1]);