libsmartcols: add printf api to fill in column data

Add new API functions using printf(3) compatible format strings to fill
in column data.

These can be used to avoid intermediate buffers in the calling
application code.

Signed-off-by: Robin Jarry <robin@jarry.cc>

diff --git a/libsmartcols/docs/libsmartcols-sections.txt b/libsmartcols/docs/libsmartcols-sections.txt
index 5b343d01eee0228ec49e296c17dec2009411daca..5f4c736a74a30bad61c6a09dd40f4d2b6811859b 100644 (file)
--- a/libsmartcols/docs/libsmartcols-sections.txt
+++ b/libsmartcols/docs/libsmartcols-sections.txt
@@ -120,6 +120,10 @@ scols_line_set_color
 scols_line_set_column_data
 scols_line_set_data
 scols_line_set_userdata
+scols_line_sprintf
+scols_line_sprintf_column
+scols_line_vprintf
+scols_line_vprintf_column
 scols_new_line
 scols_ref_line
 scols_unref_line

diff --git a/libsmartcols/src/libsmartcols.h.in b/libsmartcols/src/libsmartcols.h.in
index c97651f35023641f5d264edfbd5ad300f46dacde..3947673ba2965cbc74ab627146996dfb90e69b23 100644 (file)
--- a/libsmartcols/src/libsmartcols.h.in
+++ b/libsmartcols/src/libsmartcols.h.in
@@ -14,6 +14,7 @@
 extern "C" {
 #endif
 
+#include <stdarg.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <sys/types.h>
@@ -291,10 +292,18 @@ extern struct libscols_cell *scols_line_get_column_cell(
                                        struct libscols_column *cl);
 extern int scols_line_set_data(struct libscols_line *ln, size_t n, const char *data);
 extern int scols_line_refer_data(struct libscols_line *ln, size_t n, char *data);
+extern int scols_line_vprintf(struct libscols_line *ln, size_t n, const char *fmt, va_list ap)
+       __attribute__((format(printf, 3, 0)));
+extern int scols_line_sprintf(struct libscols_line *ln, size_t n, const char *fmt, ...)
+       __attribute__((format(printf, 3, 4)));
 extern int scols_line_is_filled(struct libscols_line *ln, size_t n);
 extern int scols_line_set_column_data(struct libscols_line *ln, struct libscols_column *cl, const char *data);
 extern const char *scols_line_get_column_data(struct libscols_line *ln, struct libscols_column *cl);
 extern int scols_line_refer_column_data(struct libscols_line *ln, struct libscols_column *cl, char *data);
+extern int scols_line_vprintf_column(struct libscols_line *ln, struct libscols_column *cl, const char *fmt, va_list ap)
+       __attribute__((format(printf, 3, 0)));
+extern int scols_line_sprintf_column(struct libscols_line *ln, struct libscols_column *cl, const char *fmt, ...)
+       __attribute__((format(printf, 3, 4)));
 extern struct libscols_line *scols_copy_line(const struct libscols_line *ln);
 
 /* table */

diff --git a/libsmartcols/src/libsmartcols.sym b/libsmartcols/src/libsmartcols.sym
index 41c74552e967d82674a7d4bf9d25ccc4ed453514..e74d928627b2d6340421a8f614ca3985ddc2ba71 100644 (file)
--- a/libsmartcols/src/libsmartcols.sym
+++ b/libsmartcols/src/libsmartcols.sym
@@ -244,3 +244,10 @@ SMARTCOLS_2.40 {
        scols_column_set_data_type;
        scols_column_get_data_type;
 } SMARTCOLS_2.39;
+
+SMARTCOLS_2.41 {
+       scols_line_vprintf;
+       scols_line_sprintf;
+       scols_line_vprintf_column;
+       scols_line_sprintf_column;
+} SMARTCOLS_2.40;

diff --git a/libsmartcols/src/line.c b/libsmartcols/src/line.c
index 2289db0f9ec4918c21923750ac575495ff570241..ffefcfba018a14fac8342bad856f83b4a4e0e5e9 100644 (file)
--- a/libsmartcols/src/line.c
+++ b/libsmartcols/src/line.c
@@ -504,6 +504,61 @@ int scols_line_refer_data(struct libscols_line *ln, size_t n, char *data)
        return scols_cell_refer_data(ce, data);
 }
 
+/**
+ * scols_line_vprintf:
+ * @ln: a pointer to a struct libscols_line instance
+ * @n: number of the cell which will refer to @data
+ * @fmt: a printf(3) compatible format string used to generate cell data
+ * @ap: a variable argument list that was initialized with va_start(3)
+ *
+ * Returns: 0, a negative value in case of an error.
+ *
+ * Since: 2.41
+ */
+int scols_line_vprintf(struct libscols_line *ln, size_t n,
+                      const char *fmt, va_list ap)
+{
+       struct libscols_cell *ce = scols_line_get_cell(ln, n);
+       char *data = NULL;
+       int ret;
+
+       if (!ce)
+               return -EINVAL;
+
+       if (vasprintf(&data, fmt, ap) < 0)
+               return errno ? -errno : -ENOMEM;
+
+       ret = scols_cell_refer_data(ce, data);
+       if (ret < 0)
+               free(data);
+
+       return ret;
+}
+
+/**
+ * scols_line_sprintf:
+ * @ln: a pointer to a struct libscols_line instance
+ * @n: number of the cell which will refer to @data
+ * @fmt: an printf(3) compatible format string used to generate cell data
+ * @...: variable argument list
+ *
+ * Returns: 0, a negative value in case of an error.
+ *
+ * Since: 2.41
+ */
+int scols_line_sprintf(struct libscols_line *ln, size_t n,
+                      const char *fmt, ...)
+{
+       va_list ap;
+       int ret;
+
+       va_start(ap, fmt);
+       ret = scols_line_vprintf(ln, n, fmt, ap);
+       va_end(ap);
+
+       return ret;
+}
+
 /**
  * scols_line_is_filled:
  * @ln: a pointer to a struct libscols_line instance
@@ -537,6 +592,55 @@ int scols_line_refer_column_data(struct libscols_line *ln,
        return scols_line_refer_data(ln, cl->seqnum, data);
 }
 
+/**
+ * scols_line_vprintf_column:
+ * @ln: a pointer to a struct libscols_line instance
+ * @cl: column, whose data is to be set
+ * @fmt: a printf(3) compatible format string used to generate column data
+ * @ap: a variable argument list that was initialized with va_start(3)
+ *
+ * The same as scols_line_vprintf() but cell is referenced by column object.
+ *
+ * Returns: 0, a negative value in case of an error.
+ *
+ * Since: 2.41
+ */
+int scols_line_vprintf_column(struct libscols_line *ln,
+                             struct libscols_column *cl,
+                             const char *fmt,
+                             va_list ap)
+{
+       return scols_line_vprintf(ln, cl->seqnum, fmt, ap);
+}
+
+
+/**
+ * scols_line_sprintf_column:
+ * @ln: a pointer to a struct libscols_line instance
+ * @cl: column, whose data is to be set
+ * @fmt: a printf(3) compatible format string used to generate column data
+ * @...: variable argument list
+ *
+ * The same as scols_line_sprintf() but cell is referenced by column object.
+ *
+ * Returns: 0, a negative value in case of an error.
+ *
+ * Since: 2.41
+ */
+int scols_line_sprintf_column(struct libscols_line *ln,
+                             struct libscols_column *cl,
+                             const char *fmt, ...)
+{
+       va_list ap;
+       int ret;
+
+       va_start(ap, fmt);
+       ret = scols_line_vprintf(ln, cl->seqnum, fmt, ap);
+       va_end(ap);
+
+       return ret;
+}
+
 /**
  * scols_copy_line:
  * @ln: a pointer to a struct libscols_line instance