/* */
/* 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. */
+/* Based on CSV format described in RFC 4180 section 2. */
/* */
-/* 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(). */
+/* Additions to RFC 4180 rules: */
+/* - delimeters and other special characters may be "escaped" by a leading */
+/* backslash (\) */
+/* - C escape sequences for newline (\n) and tab (\t) are also translated. */
+/* - if quoted text is not followed by a delimeter, any additional text is */
+/* concatenated with quoted portion. */
/* */
/* Returns a list of fields. A blank line is considered a line with one */
/* empty field. Returns empty (NULL) when done. */
parse_line (FILE *fp,
gchar delim )
{
- GList *list = NULL;
- GString *string;
- gint c;
- enum { BEGIN, NORMAL, QUOTED, QUOTED_QUOTE1,
- NORMAL_ESCAPED, QUOTED_ESCAPED, DONE } state;
+ GList *list;
+ GString *field;
+ gint c;
+ enum { DELIM,
+ QUOTED, QUOTED_QUOTE1, QUOTED_ESCAPED,
+ SIMPLE, SIMPLE_ESCAPED,
+ DONE } state;
if (fp == NULL) {
return NULL;
}
- state = BEGIN;
- string = g_string_new( "" );
+ state = DELIM;
+ list = NULL;
+ field = g_string_new( "" );
while ( state != DONE ) {
c=getc (fp);
switch (state) {
- case BEGIN:
- if ( c == delim )
- {
- /* first field is empty. */
- list = g_list_append (list, g_strdup (""));
- state = NORMAL;
- break;
- }
+ case DELIM:
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':
- /* treat as one empty field. */
+ /* last field is empty. */
list = g_list_append (list, g_strdup (""));
state = DONE;
break;
+ case '\r':
+ /* ignore */
+ state = DELIM;
+ break;
case EOF:
/* end of file, no more lines. */
state = DONE;
break;
- default:
- 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);
+ /* start a quoted field. */
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;
+ /* simple field, but 1st character is an escape. */
+ state = SIMPLE_ESCAPED;
break;
default:
- string = g_string_append_c (string, c);
- state = NORMAL;
+ if ( c == delim )
+ {
+ /* field is empty. */
+ list = g_list_append (list, g_strdup (""));
+ state = DELIM;
+ }
+ else
+ {
+ /* begining of a simple field. */
+ field = g_string_append_c (field, c);
+ state = SIMPLE;
+ }
break;
}
break;
case QUOTED:
switch (c) {
+ case EOF:
+ /* File ended mid way through quoted item, truncate field. */
+ list = g_list_append (list, g_strdup (field->str));
+ state = DONE;
+ break;
case '"':
- string = g_string_append_c (string, c);
+ /* Possible end of field, but could be 1st of a pair. */
state = QUOTED_QUOTE1;
break;
case '\\':
- string = g_string_append_c (string, c);
+ /* Escape next character, or special escape, e.g. \n. */
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);
+ /* Use character literally. */
+ field = g_string_append_c (field, 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:
/* line or file ended after quoted item */
- list = g_list_append (list, parse_field (string->str));
+ list = g_list_append (list, g_strdup (field->str));
state = DONE;
break;
- default:
- string = g_string_append_c (string, c);
- state = NORMAL;
+ case '"':
+ /* second quote, insert and stay quoted. */
+ field = g_string_append_c (field, c);
+ state = QUOTED;
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;
+ case '\r':
+ /* ignore and go to fallback */
+ state = SIMPLE;
break;
default:
- string = g_string_append_c (string, c);
- state = NORMAL;
+ if ( c == delim )
+ {
+ /* end of field. */
+ list = g_list_append (list, g_strdup (field->str));
+ field = g_string_assign( field, "" );
+ state = DELIM;
+ }
+ else
+ {
+ /* fallback if not a delim or another quote. */
+ field = g_string_append_c (field, c);
+ state = SIMPLE;
+ }
break;
}
break;
switch (c) {
case EOF:
/* File ended mid way through quoted item */
- list = g_list_append (list, parse_field (string->str));
+ list = g_list_append (list, g_strdup (field->str));
state = DONE;
break;
- default:
- string = g_string_append_c (string, c);
+ case 'n':
+ /* Decode "\n" as newline. */
+ field = g_string_append_c (field, '\n');
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 '"':
+ case 't':
+ /* Decode "\t" as tab. */
+ field = g_string_append_c (field, '\t');
state = QUOTED;
break;
- case '\r':
- /* Strip CR. */
- break;
default:
- string = g_string_append_c (string, *c);
+ /* Use character literally. */
+ field = g_string_append_c (field, c);
+ state = QUOTED;
break;
}
break;
- case NORMAL_ESCAPED:
- switch (*c) {
- case 'n':
- string = g_string_append_c (string, '\n');
- state = NORMAL;
- break;
- case 't':
- string = g_string_append_c (string, '\t');
- state = NORMAL;
+ case SIMPLE:
+ switch (c) {
+ case '\n':
+ case EOF:
+ /* line or file ended */
+ list = g_list_append (list, g_strdup (field->str));
+ state = DONE;
break;
- default:
- string = g_string_append_c (string, *c);
- state = NORMAL;
+ case '\r':
+ /* ignore */
+ state = SIMPLE;
break;
- }
- break;
-
- case QUOTED:
- switch (*c) {
case '\\':
- state = QUOTED_ESCAPED;
- break;
- case '"':
- state = QUOTED_QUOTE1;
- break;
- case '\r':
- /* Strip CR. */
+ /* Escape next character, or special escape, e.g. \n. */
+ state = SIMPLE_ESCAPED;
break;
default:
- string = g_string_append_c (string, *c);
+ if ( c == delim )
+ {
+ /* end of field. */
+ list = g_list_append (list, g_strdup (field->str));
+ field = g_string_assign( field, "" );
+ state = DELIM;
+ }
+ else
+ {
+ /* Use character literally. */
+ field = g_string_append_c (field, c);
+ state = SIMPLE;
+ }
break;
}
break;
- case QUOTED_ESCAPED:
- switch (*c) {
- case 'n':
- string = g_string_append_c (string, '\n');
- state = QUOTED;
- break;
- case 't':
- string = g_string_append_c (string, '\t');
- state = QUOTED;
- break;
- default:
- string = g_string_append_c (string, *c);
- state = QUOTED;
+ case SIMPLE_ESCAPED:
+ switch (c) {
+ case EOF:
+ /* File ended mid way through quoted item */
+ list = g_list_append (list, g_strdup (field->str));
+ state = DONE;
break;
- }
- break;
-
- case QUOTED_QUOTE1:
- switch (*c) {
- case '"':
- /* insert quotes in string, stay quoted. */
- string = g_string_append_c (string, *c);
- state = QUOTED;
+ case 'n':
+ /* Decode "\n" as newline. */
+ field = g_string_append_c (field, '\n');
+ state = SIMPLE;
break;
- case '\r':
- /* Strip CR, return to QUOTED. */
- state = QUOTED;
+ case 't':
+ /* Decode "\t" as tab. */
+ field = g_string_append_c (field, '\t');
+ state = SIMPLE;
break;
default:
- string = g_string_append_c (string, *c);
- state = NORMAL;
+ /* Use character literally. */
+ field = g_string_append_c (field, c);
+ state = SIMPLE;
break;
}
break;
}
}
+ g_string_free( field, TRUE );
- field = g_strdup (string->str);
- g_string_free( string, TRUE );
- g_free (pass1_field);
-
- return field;
+ return list;
}
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