I wonder how to use struct column_info to display the packet,what is the relationship between column_info with packet_list?
the following is the definition of struct column_info :
/** Column info */
typedef struct _column_info {
gint num_cols; /**< Number of columns */
gint *col_fmt; /**< Format of column */
gboolean **fmt_matx; /**< Specifies which formats apply to a column */
gint *col_first; /**< First column number with a given format */
gint *col_last; /**< Last column number with a given format */
gchar **col_title; /**< Column titles */
gchar **col_custom_field; /**< Custom column field */
gint *col_custom_occurrence;/**< Custom column field occurrence */
gint *col_custom_field_id; /**< Custom column field id */
struct _dfilter_t **col_custom_dfilter; /**< Compiled custom column field */
const gchar **col_data; /**< Column data */
gchar **col_buf; /**< Buffer into which to copy data for column */
int *col_fence; /**< Stuff in column buffer before this index is immutable */
col_expr_t col_expr; /**< Column expressions and values */
gboolean writable; /**< writable or not @todo Are we still writing to the columns? */
gboolean columns_changed; /**< Have the columns been changed in the prefs? */
} column_info;
