libsmartcols: add functions to control terminal usage

Signed-off-by: Karel Zak <kzak@redhat.com>

libsmartcols/docs/libsmartcols-sections.txt

@@ -96,6 +96,7 @@ libscols_table
 scols_copy_table
 scols_new_table
 scols_ref_table
+scols_sort_table
 scols_table_add_column
 scols_table_add_line
 scols_table_colors_wanted
@@ -115,6 +116,9 @@ scols_table_get_line_separator
 scols_table_get_ncols
 scols_table_get_nlines
 scols_table_get_stream
+scols_table_get_termforce
+scols_table_get_termwidth
+scols_table_get_title
 scols_table_is_ascii
 scols_table_is_empty
 scols_table_is_export
@@ -137,8 +141,8 @@ scols_table_set_line_separator
 scols_table_set_name
 scols_table_set_stream
 scols_table_set_symbols
-scols_table_get_title
-scols_sort_table
+scols_table_set_termforce
+scols_table_set_termwidth
 scols_unref_table
 </SECTION>
 

libsmartcols/src/libsmartcols.h.in

@@ -246,6 +246,20 @@ extern int scols_table_reduce_termwidth(struct libscols_table *tb, size_t reduce
 
 extern int scols_sort_table(struct libscols_table *tb, struct libscols_column *cl);
 
+/*
+ *
+ */
+enum {
+	SCOLS_TERMFORCE_AUTO = 0,
+	SCOLS_TERMFORCE_NEVER,
+	SCOLS_TERMFORCE_ALWAYS
+};
+extern int scols_table_set_termforce(struct libscols_table *tb, int force);
+extern int scols_table_get_termforce(struct libscols_table *tb);
+extern int scols_table_set_termwidth(struct libscols_table *tb, size_t width);
+extern size_t scols_table_get_termwidth(struct libscols_table *tb);
+
+
 /* table_print.c */
 extern int scols_print_table(struct libscols_table *tb);
 extern int scols_print_table_to_string(struct libscols_table *tb, char **data);

libsmartcols/src/libsmartcols.sym

@@ -141,4 +141,8 @@ SMARTCOLS_2.29 {
 global:
 	scols_column_is_wrapnl;
 	scols_symbols_set_cell_padding;
+	scols_table_get_termforce;
+	scols_table_get_termwidth;
+	scols_table_set_termforce;
+	scols_table_set_termwidth;
 } SMARTCOLS_2.28;

libsmartcols/src/smartcolsP.h

@@ -139,6 +139,7 @@ struct libscols_table {
 	size_t	nlines;		/* number of lines */
 	size_t	termwidth;	/* terminal width */
 	size_t  termreduce;	/* extra blank space */
+	int	termforce;	/* SCOLS_TERMFORCE_* */
 	FILE	*out;		/* output stream */
 
 	char	*colsep;	/* column separator */

libsmartcols/src/table.c

@@ -25,6 +25,7 @@
 #include <ctype.h>
 
 #include "nls.h"
+#include "ttyutils.h"
 #include "smartcolsP.h"
 
 #ifdef HAVE_WIDECHAR
@@ -1104,3 +1105,61 @@ int scols_sort_table(struct libscols_table *tb, struct libscols_column *cl)
 	list_sort(&tb->tb_lines, cells_cmp_wrapper, cl);
 	return 0;
 }
+
+/**
+ * scols_table_set_termforce:
+ * @tb: table
+ * @force: SCOLS_TERMFORCE_{NEVER,ALWAYS,AUTO}
+ *
+ * Forces library to use stdout as terminal, non-terminal or use automatical
+ * detection (default).
+ *
+ * Returns: 0, a negative value in case of an error.
+ */
+int scols_table_set_termforce(struct libscols_table *tb, int force)
+{
+	if (!tb)
+		return -EINVAL;
+	tb->termforce = force;
+	return 0;
+}
+
+/**
+ * scols_table_get_termforce:
+ * @tb: table
+ *
+ * Returns: SCOLS_TERMFORCE_{NEVER,ALWAYS,AUTO} or a negative value in case of an error.
+ */
+int scols_table_get_termforce(struct libscols_table *tb)
+{
+	return tb->termforce;
+}
+
+/**
+ * scols_table_set_termwidth
+ * @tb: table
+ * @width: terminal width
+ *
+ * The library automatically detects terminal width or defaults to 80 chars if
+ * detections is unsuccessful. This function override this behaviour.
+ *
+ * Returns: 0, a negative value in case of an error.
+ */
+int scols_table_set_termwidth(struct libscols_table *tb, size_t width)
+{
+	tb->termwidth = width;
+	return 0;
+}
+
+/**
+ * scols_table_get_termwidth
+ * @tb: table
+ *
+ * Returns: terminal width or a negative value in case of an error.
+ */
+size_t scols_table_get_termwidth(struct libscols_table *tb)
+{
+	if (tb->termwidth == 0)
+		tb->termwidth = get_terminal_width(80);
+	return tb->termwidth;
+}

libsmartcols/src/table_print.c

@@ -23,7 +23,6 @@
 #include <ctype.h>
 
 #include "mbsalign.h"
-#include "ttyutils.h"
 #include "carefulputc.h"
 #include "smartcolsP.h"
 
@@ -1334,13 +1333,18 @@ static int initialize_printing(struct libscols_table *tb, struct libscols_buffer
 		scols_table_set_symbols(tb, NULL);	/* use default */
 
 	if (tb->format == SCOLS_FMT_HUMAN)
-		tb->is_term = isatty(STDOUT_FILENO) ? 1 : 0;
+		tb->is_term = tb->termforce == SCOLS_TERMFORCE_NEVER  ? 0 :
+			      tb->termforce == SCOLS_TERMFORCE_ALWAYS ? 1 :
+			      isatty(STDOUT_FILENO);
 
 	if (tb->is_term) {
-		tb->termwidth = get_terminal_width(80);
-		if (tb->termreduce > 0 && tb->termreduce < tb->termwidth)
-			tb->termwidth -= tb->termreduce;
-		bufsz = tb->termwidth;
+		size_t width = (size_t) scols_table_get_termwidth(tb);
+
+		if (tb->termreduce > 0 && tb->termreduce < width) {
+			width -= tb->termreduce;
+			scols_table_set_termwidth(tb, width);
+		}
+		bufsz = width;
 	} else
 		bufsz = BUFSIZ;