static GList *parse_line (FILE *fp,
gchar delim);
+static gchar *parse_field (gchar *raw_field);
static void free_fields (GList **fields);
\f
}
/*---------------------------------------------------------------------------*/
-/* PRIVATE. Parse line (quoted values may span multiple lines). */
+/* PRIVATE. Parse line. */
+/* */
+/* Attempt to be a robust parser of various CSV (and similar) formats. */
+/* */
+/* Split into fields, accounting for: */
+/* - delimeters may be embedded in quoted text (") */
+/* - delimeters may be "escaped" by a leading backslash (\) */
+/* - quotes may be embedded in quoted text as two adjacent quotes ("") */
+/* - quotes may be "escaped" either within or outside of quoted text. */
+/* - newlines may be embedded in quoted text, allowing a field to span */
+/* more than one line. */
+/* */
+/* This function does not do any parsing of the individual fields, other */
+/* than to correctly interpet delimeters. Actual parsing of the individual */
+/* fields is done in parse_field(). */
+/* */
+/* Returns a list of fields. A blank line is considered a line with one */
+/* empty field. Returns empty (NULL) when done. */
/*---------------------------------------------------------------------------*/
static GList *
parse_line (FILE *fp,
GList *list = NULL;
GString *string;
gint c;
- enum { BEGIN, NORMAL, NORMAL_ESCAPED,
- QUOTED, QUOTED_ESCAPED, QUOTED_QUOTE1,
- DONE } state;
+ enum { BEGIN, NORMAL, QUOTED, QUOTED_QUOTE1,
+ NORMAL_ESCAPED, QUOTED_ESCAPED, DONE } state;
state = BEGIN;
string = g_string_new( "" );
switch (state) {
case BEGIN:
+ if ( c == delim )
+ {
+ /* first field is empty. */
+ list = g_list_append (list, g_strdup (""));
+ state = NORMAL;
+ break;
+ }
switch (c) {
- case '\\':
- state = NORMAL_ESCAPED;
- break;
case '"':
+ string = g_string_append_c (string, c);
state = QUOTED;
break;
- case '\r':
- /* Strip CR. */
- state = NORMAL;
+ case '\\':
+ string = g_string_append_c (string, c);
+ state = NORMAL_ESCAPED;
break;
case '\n':
/* treat as one empty field. */
- list = g_list_append (list,
- g_strdup (""));
+ list = g_list_append (list, g_strdup (""));
state = DONE;
break;
case EOF:
+ /* end of file, no more lines. */
state = DONE;
break;
default:
- if ( c != delim ) {
- string = g_string_append_c (string, c);
- } else {
- list = g_list_append (list,
- g_strdup (string->str));
- string = g_string_assign( string, "" );
- }
+ string = g_string_append_c (string, c);
state = NORMAL;
break;
}
break;
case NORMAL:
+ if ( c == delim )
+ {
+ list = g_list_append (list, parse_field (string->str));
+ string = g_string_assign( string, "" );
+ state = NORMAL;
+ break;
+ }
switch (c) {
+ case '"':
+ string = g_string_append_c (string, c);
+ state = QUOTED;
+ break;
case '\\':
+ string = g_string_append_c (string, c);
state = NORMAL_ESCAPED;
break;
+ case '\n':
+ case EOF:
+ list = g_list_append (list, parse_field (string->str));
+ state = DONE;
+ break;
+ default:
+ string = g_string_append_c (string, c);
+ state = NORMAL;
+ break;
+ }
+ break;
+
+ case QUOTED:
+ switch (c) {
case '"':
- state = QUOTED;
+ string = g_string_append_c (string, c);
+ state = QUOTED_QUOTE1;
break;
- case '\r':
- /* Strip CR. */
+ case '\\':
+ string = g_string_append_c (string, c);
+ state = QUOTED_ESCAPED;
+ break;
+ case EOF:
+ /* File ended mid way through quoted item */
+ list = g_list_append (list, parse_field (string->str));
+ state = DONE;
+ break;
+ default:
+ string = g_string_append_c (string, c);
+ break;
+ }
+ break;
+
+ case QUOTED_QUOTE1:
+ if ( c == delim )
+ {
+ list = g_list_append (list, parse_field (string->str));
+ string = g_string_assign( string, "" );
+ state = NORMAL;
+ break;
+ }
+ switch (c) {
+ case '"':
+ /* insert quotes in string, stay quoted. */
+ string = g_string_append_c (string, c);
+ state = QUOTED;
break;
case '\n':
case EOF:
- list = g_list_append (list,
- g_strdup (string->str));
+ /* line or file ended after quoted item */
+ list = g_list_append (list, parse_field (string->str));
state = DONE;
break;
default:
- if ( c != delim ) {
- string = g_string_append_c (string, c);
- } else {
- list = g_list_append (list,
- g_strdup (string->str));
- string = g_string_assign( string, "" );
- }
+ string = g_string_append_c (string, c);
+ state = NORMAL;
break;
}
break;
case NORMAL_ESCAPED:
switch (c) {
+ case EOF:
+ /* File ended mid way through quoted item */
+ list = g_list_append (list, parse_field (string->str));
+ state = DONE;
+ break;
+ default:
+ string = g_string_append_c (string, c);
+ state = NORMAL;
+ break;
+ }
+ break;
+
+ case QUOTED_ESCAPED:
+ switch (c) {
+ case EOF:
+ /* File ended mid way through quoted item */
+ list = g_list_append (list, parse_field (string->str));
+ state = DONE;
+ break;
+ default:
+ string = g_string_append_c (string, c);
+ state = QUOTED;
+ break;
+ }
+ break;
+
+ default:
+ g_assert_not_reached();
+ break;
+ }
+
+ }
+ g_string_free( string, TRUE );
+
+ return list;
+}
+
+/*---------------------------------------------------------------------------*/
+/* PRIVATE. Parse field. */
+/* */
+/* - Strip leading and trailing white space, unless quoted. */
+/* - Strip CR, unless escaped. */
+/* - Expand '\n' and '\t' into newline and tab characters. */
+/* - Remove quotes, unless escaped (\" anywhere or "" within quotes) */
+/*---------------------------------------------------------------------------*/
+static gchar *
+parse_field (gchar *raw_field)
+{
+ GString *string;
+ gchar *pass1_field, *c, *field;
+ enum { NORMAL, NORMAL_ESCAPED, QUOTED, QUOTED_ESCAPED, QUOTED_QUOTE1} state;
+
+
+ /*
+ * Pass 1: remove leading and trailing spaces.
+ */
+ pass1_field = g_strdup (raw_field);
+ g_strstrip (pass1_field);
+
+ /*
+ * Pass 2: resolve quoting and escaping.
+ */
+ state = NORMAL;
+ string = g_string_new( "" );
+ for ( c=pass1_field; *c != 0; c++ )
+ {
+ switch (state) {
+
+ case NORMAL:
+ switch (*c) {
+ case '\\':
+ state = NORMAL_ESCAPED;
+ break;
+ case '"':
+ state = QUOTED;
+ break;
+ case '\r':
+ /* Strip CR. */
+ break;
+ default:
+ string = g_string_append_c (string, *c);
+ break;
+ }
+ break;
+
+ case NORMAL_ESCAPED:
+ switch (*c) {
case 'n':
string = g_string_append_c (string, '\n');
state = NORMAL;
string = g_string_append_c (string, '\t');
state = NORMAL;
break;
- case '\r':
- /* Strip CR, stay ESCAPED. */
- break;
- case EOF:
- state = DONE;
- break;
default:
- string = g_string_append_c (string, c);
+ string = g_string_append_c (string, *c);
state = NORMAL;
break;
}
break;
case QUOTED:
- switch (c) {
+ switch (*c) {
case '\\':
state = QUOTED_ESCAPED;
break;
case '\r':
/* Strip CR. */
break;
- case EOF:
- /* File ended mid way through quoted item */
- list = g_list_append (list,
- g_strdup (string->str));
- state = DONE;
- break;
default:
- string = g_string_append_c (string, c);
+ string = g_string_append_c (string, *c);
break;
}
break;
case QUOTED_ESCAPED:
- switch (c) {
+ switch (*c) {
case 'n':
string = g_string_append_c (string, '\n');
state = QUOTED;
string = g_string_append_c (string, '\t');
state = QUOTED;
break;
- case '\r':
- /* Strip CR, stay ESCAPED. */
- break;
- case EOF:
- /* File ended mid way through quoted item */
- list = g_list_append (list,
- g_strdup (string->str));
- state = DONE;
- break;
default:
- string = g_string_append_c (string, c);
+ string = g_string_append_c (string, *c);
state = QUOTED;
break;
}
break;
case QUOTED_QUOTE1:
- switch (c) {
+ switch (*c) {
case '"':
/* insert quotes in string, stay quoted. */
- string = g_string_append_c (string, c);
+ string = g_string_append_c (string, *c);
state = QUOTED;
break;
case '\r':
- /* Strip CR, return to NORMAL. */
- state = NORMAL;
- break;
- case '\n':
- case EOF:
- /* line or file ended after quoted item */
- list = g_list_append (list,
- g_strdup (string->str));
- state = DONE;
+ /* Strip CR, return to QUOTED. */
+ state = QUOTED;
break;
default:
- if ( c != delim ) {
- string = g_string_append_c (string, c);
- } else {
- list = g_list_append (list,
- g_strdup (string->str));
- string = g_string_assign( string, "" );
- }
+ string = g_string_append_c (string, *c);
state = NORMAL;
break;
}
}
}
+
+ field = g_strdup (string->str);
g_string_free( string, TRUE );
+ g_free (pass1_field);
- return list;
+ return field;
}
/*---------------------------------------------------------------------------*/
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