iconv: use temporary file for output

On Linux iconv allows the output file specified with '-o' to be
the same as the input file.  Do the same for our version by creating
a temporary output file and renaming it on completion.

Costs 64-88 bytes.

1 files changed, 11 insertions, 2 deletions

diff --git a/miscutils/iconv.c b/miscutils/iconv.c
index ec3c0c92d..debb45704 100644
--- a/miscutils/iconv.c
+++ b/miscutils/iconv.c
@@ -1717,6 +1717,7 @@ int iconv_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int iconv_main(int argc, char **argv)
 {
         const char *fromcode = "", *tocode = "", *outfile;
+        char *tmpname = NULL;
         int i, opt;
         iconv_t cd;
         FILE *in;
@@ -1733,8 +1734,11 @@ int iconv_main(int argc, char **argv)
                 return 0;
         }
 
-        if (opt & OPT_o)
-                out = xfopen(outfile, "wb");
+        if (opt & OPT_o) {
+                tmpname = xasprintf("%sXXXXXX", outfile);
+                mktemp(tmpname);
+                out = xfopen(tmpname, "wb");
+        }
 
         if (opt & OPT_c)
                 tocode = xasprintf("%s//IGNORE", tocode);
@@ -1755,6 +1759,11 @@ int iconv_main(int argc, char **argv)
                 fclose(in);
         }
 
+        if (tmpname) {
+                fclose(out);
+                xrename(tmpname, outfile);
+        }
+
         if (ENABLE_FEATURE_CLEAN_UP)
                 iconv_close(cd);
         return 0;