play: Convert com_ls() to lopsub.

[paraslash.git] / string.c

diff --git a/string.c b/string.c
index d9dcc62d2ea45efc6a3c2899185a2033d5e74339..6033a008dbf154953de673f85048eb78812d1722 100644 (file)
--- a/string.c
+++ b/string.c
@@ -6,19 +6,16 @@
 
 /** \file string.c Memory allocation and string handling functions. */
 
-#define _GNU_SOURCE
+#include "para.h"
 
 #include <pwd.h>
 #include <sys/utsname.h> /* uname() */
-
 #include <string.h>
 #include <regex.h>
-
 #include <langinfo.h>
 #include <wchar.h>
 #include <wctype.h>
 
-#include "para.h"
 #include "string.h"
 #include "error.h"
 
@@ -806,15 +803,18 @@ err:
  * Split a buffer into words.
  *
  * This parser honors single and double quotes, backslash-escaped characters
- * and special characters like \p \\n. The result contains pointers to copies
- * of the words contained in \a buf and has to be freed by using \ref
- * free_argv().
+ * and special characters like \\n. The result contains pointers to copies of
+ * the words contained in buf and has to be freed by using \ref free_argv().
  *
  * \param buf The buffer to be split.
  * \param delim Each character in this string is treated as a separator.
  * \param result The array of words is returned here.
  *
- * \return Number of words in \a buf, negative on errors.
+ * It's OK to pass NULL as the buffer argument. This is equivalent to passing
+ * the empty string.
+ *
+ * \return Number of words in buf, negative on errors. The array returned
+ * through the result pointer is NULL terminated.
  */
 int create_argv(const char *buf, const char *delim, char ***result)
 {
@@ -1070,3 +1070,66 @@ __must_check int strwidth(const char *s, size_t *result)
        free(dest);
        return 1;
 }
+
+/**
+ * Truncate and sanitize a (wide character) string.
+ *
+ * This replaces all non-printable characters by spaces and makes sure that the
+ * modified string does not exceed the given maximal width.
+ *
+ * \param src The source string in multi-byte form.
+ * \param max_width The maximal number of cells the result may occupy.
+ * \param result Sanitized multi-byte string, must be freed by caller.
+ * \param width The width of the sanitized string, always <= max_width.
+ *
+ * The function is wide-character aware but falls back to C strings for
+ * non-UTF-8 locales.
+ *
+ * \return Standard. On success, *result points to a sanitized copy of the
+ * given string. This copy was allocated with malloc() and should hence be
+ * freed when the caller is no longer interested in the result.
+ *
+ * The function fails if the given string contains an invalid multibyte
+ * sequence. In this case, *result is set to NULL, and *width to zero.
+ */
+__must_check int sanitize_str(const char *src, size_t max_width,
+               char **result, size_t *width)
+{
+       mbstate_t state;
+       static wchar_t *wcs;
+       size_t num_wchars, n;
+
+       if (!utf8_mode()) {
+               *result = para_strdup(src);
+               /* replace non-printable characters by spaces */
+               for (n = 0; n < max_width && src[n]; n++) {
+                       if (!isprint((unsigned char)src[n]))
+                               (*result)[n] = ' ';
+               }
+               (*result)[n] = '\0';
+               *width = n;
+               return 0;
+       }
+       *result = NULL;
+       *width = 0;
+       memset(&state, 0, sizeof(state));
+       num_wchars = mbsrtowcs(NULL, &src, 0, &state);
+       if (num_wchars == (size_t)-1)
+               return -ERRNO_TO_PARA_ERROR(errno);
+       wcs = para_malloc((num_wchars + 1) * sizeof(*wcs));
+       memset(&state, 0, sizeof(state));
+       num_wchars = mbsrtowcs(wcs, &src, num_wchars + 1, &state);
+       assert(num_wchars != (size_t)-1);
+       for (n = 0; n < num_wchars && *width < max_width; n++) {
+               if (!iswprint(wcs[n]))
+                       wcs[n] = L' ';
+               *width += xwcwidth(wcs[n], *width);
+       }
+       wcs[n] = L'\0';
+       n = wcstombs(NULL, wcs, 0) + 1;
+       *result = para_malloc(n);
+       num_wchars = wcstombs(*result, wcs, n);
+       assert(num_wchars != (size_t)-1);
+       free(wcs);
+       return 1;
+}