libmount: add functions to handle comments in fs tables

[thirdparty/util-linux.git] / libmount / src / tab.c

diff --git a/libmount/src/tab.c b/libmount/src/tab.c
index b3e47bd6e791005a3f511c980c6443cb2abea4e1..5ac252ce1994ff898e869b59dcd03961e56c2d4f 100644 (file)
--- a/libmount/src/tab.c
+++ b/libmount/src/tab.c
@@ -110,6 +110,8 @@ void mnt_free_table(struct libmnt_table *tb)
        mnt_reset_table(tb);
 
        DBG(TAB, mnt_debug_h(tb, "free"));
+       free(tb->comm_intro);
+       free(tb->comm_tail);
        free(tb);
 }
 
@@ -125,6 +127,148 @@ int mnt_table_get_nents(struct libmnt_table *tb)
        return tb ? tb->nents : 0;
 }
 
+/**
+ * mnt_table_enable_comments:
+ * @tb: pointer to tab
+ *
+ * Enables parsing of comments.
+ *
+ * The initial (intro) file comment is accessible by
+ * mnt_table_get_intro_comment(). The intro and the comment of the first fstab
+ * entry has to be separated by blank line.  The filesystem comments are
+ * accessible by mnt_fs_get_comment(). The tailing fstab comment is accessible
+ * by mnt_table_get_tailing_comment().
+ *
+ * <informalexample>
+ *  <programlisting>
+ *     #
+ *     # Intro comment
+ *     #
+ *
+ *     # this comments belongs to the first fs
+ *     LABEL=foo /mnt/foo auto defaults 1 2
+ *     # this comments belongs to the second fs
+ *     LABEL=bar /mnt/bar auto defaults 1 2 
+ *     # tailing comment
+ *  </programlisting>
+ * </informalexample>
+ */
+void mnt_table_enable_comments(struct libmnt_table *tb, int enable)
+{
+       assert(tb);
+       if (tb)
+               tb->comms = enable;
+}
+
+/**
+ * mnt_table_get_intro_comment:
+ * @tb: pointer to tab
+ *
+ * Returns: initial comment in tb
+ */
+const char *mnt_table_get_intro_comment(struct libmnt_table *tb)
+{
+       assert(tb);
+       return tb ? tb->comm_intro : NULL;
+}
+
+/**
+ * mnt_table_set_into_comment:
+ * @tb: pointer to tab
+ * @comm: comment or NULL
+ *
+ * Sets initial comment in tb.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_set_intro_comment(struct libmnt_table *tb, const char *comm)
+{
+       char *p = NULL;
+
+       assert(tb);
+       if (!tb)
+               return -EINVAL;
+       if (comm) {
+               p = strdup(comm);
+               if (!p)
+                       return -ENOMEM;
+       }
+       free(tb->comm_intro);
+       tb->comm_intro = p;
+       return 0;
+}
+
+/**
+ * mnt_table_append_into_comment:
+ * @tb: pointer to tab
+ * @comm: comment of NULL
+ *
+ * Appends the initial comment in tb.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_append_intro_comment(struct libmnt_table *tb, const char *comm)
+{
+       assert(tb);
+       if (!tb)
+               return -EINVAL;
+       return append_string(&tb->comm_intro, comm);
+}
+
+/**
+ * mnt_table_get_tailing_comment:
+ * @tb: pointer to tab
+ *
+ * Returns: table tailing comment
+ */
+const char *mnt_table_get_tailing_comment(struct libmnt_table *tb)
+{
+       assert(tb);
+       return tb ? tb->comm_tail : NULL;
+}
+
+/**
+ * mnt_table_set_tailing_comment
+ * @tb: pointer to tab
+ *
+ * Sets tailing comment in table.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_set_tailing_comment(struct libmnt_table *tb, const char *comm)
+{
+       char *p = NULL;
+
+       assert(tb);
+       if (!tb)
+               return -EINVAL;
+       if (comm) {
+               p = strdup(comm);
+               if (!p)
+                       return -ENOMEM;
+       }
+       free(tb->comm_tail);
+       tb->comm_tail = p;
+       return 0;
+}
+
+/**
+ * mnt_table_append_tailing_comment:
+ * @tb: pointer to tab
+ * @comm: comment of NULL
+ *
+ * Appends to the tailing table comment.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_append_tailing_comment(struct libmnt_table *tb, const char *comm)
+{
+       assert(tb);
+       if (!tb)
+               return -EINVAL;
+       return append_string(&tb->comm_tail, comm);
+}
+
 /**
  * mnt_table_set_cache:
  * @tb: pointer to tab
@@ -1079,7 +1223,7 @@ static int parser_errcb(struct libmnt_table *tb, const char *filename, int line)
        return 1;       /* all errors are recoverable -- this is default */
 }
 
-struct libmnt_table *create_table(const char *file)
+struct libmnt_table *create_table(const char *file, int comments)
 {
        struct libmnt_table *tb;
 
@@ -1089,6 +1233,7 @@ struct libmnt_table *create_table(const char *file)
        if (!tb)
                goto err;
 
+       mnt_table_enable_comments(tb, comments);
        mnt_table_set_parser_errcb(tb, parser_errcb);
 
        if (mnt_table_parse_file(tb, file) != 0)
@@ -1106,7 +1251,7 @@ int test_copy_fs(struct libmnt_test *ts, int argc, char *argv[])
        struct libmnt_fs *fs;
        int rc = -1;
 
-       tb = create_table(argv[1]);
+       tb = create_table(argv[1], FALSE);
        if (!tb)
                return -1;
 
@@ -1136,8 +1281,12 @@ int test_parse(struct libmnt_test *ts, int argc, char *argv[])
        struct libmnt_iter *itr = NULL;
        struct libmnt_fs *fs;
        int rc = -1;
+       int parse_comments = FALSE;
+
+       if (argc == 3 && !strcmp(argv[2], "--comments"))
+               parse_comments = TRUE;
 
-       tb = create_table(argv[1]);
+       tb = create_table(argv[1], parse_comments);
        if (!tb)
                return -1;
 
@@ -1145,8 +1294,16 @@ int test_parse(struct libmnt_test *ts, int argc, char *argv[])
        if (!itr)
                goto done;
 
+       if (mnt_table_get_intro_comment(tb))
+               fprintf(stdout, "Initial comment:\n\"%s\"\n",
+                               mnt_table_get_intro_comment(tb));
+
        while(mnt_table_next_fs(tb, itr, &fs) == 0)
                mnt_fs_print_debug(fs, stdout);
+
+       if (mnt_table_get_tailing_comment(tb))
+               fprintf(stdout, "Trailing comment:\n\"%s\"\n",
+                               mnt_table_get_tailing_comment(tb));
        rc = 0;
 done:
        mnt_free_iter(itr);
@@ -1169,7 +1326,7 @@ int test_find(struct libmnt_test *ts, int argc, char *argv[], int dr)
 
        file = argv[1], find = argv[2], what = argv[3];
 
-       tb = create_table(file);
+       tb = create_table(file, FALSE);
        if (!tb)
                goto done;
 
@@ -1213,7 +1370,7 @@ int test_find_pair(struct libmnt_test *ts, int argc, char *argv[])
        struct libmnt_cache *mpc = NULL;
        int rc = -1;
 
-       tb = create_table(argv[1]);
+       tb = create_table(argv[1], FALSE);
        if (!tb)
                return -1;
        mpc = mnt_new_cache();
@@ -1274,7 +1431,7 @@ static int test_is_mounted(struct libmnt_test *ts, int argc, char *argv[])
                return -1;
        }
 
-       fstab = create_table(argv[1]);
+       fstab = create_table(argv[1], FALSE);
        if (!fstab)
                goto done;
 
@@ -1310,7 +1467,7 @@ done:
 int main(int argc, char *argv[])
 {
        struct libmnt_test tss[] = {
-       { "--parse",    test_parse,        "<file>  parse and print tab" },
+       { "--parse",    test_parse,        "<file> [--comments] parse and print tab" },
        { "--find-forward",  test_find_fw, "<file> <source|target> <string>" },
        { "--find-backward", test_find_bw, "<file> <source|target> <string>" },
        { "--find-pair",     test_find_pair, "<file> <source> <target>" },