1 files changed, 44 insertions, 0 deletions
diff --git a/bintrim.c b/bintrim.c
new file mode 100644
index 0000000..2a2018e
--- /dev/null
+++ b/bintrim.c
@@ -0,0 +1,44 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <err.h>
+
+int
+main(int argc, const char *argv[])
+{
+   unsigned char trim = 0;
+
+   if (argc > 1)
+      trim = strtoul(argv[1], NULL, 10);
+
+   bool leading = true;
+   size_t rd, out_sz = 0, out_allocated = 0;
+   char buf[4096], *out = NULL;
+   while ((rd = fread(buf, 1, sizeof(buf), stdin))) {
+      for (const char *s = buf; s < buf + rd; ++s) {
+         if (*s == trim && leading)
+            continue;
+
+         if (out_sz >= out_allocated) {
+            if (!(out = realloc(out, out_allocated += sizeof(buf))))
+               err(EXIT_FAILURE, "realloc");
+         }
+
+         out[out_sz++] = *s;
+         leading = false;
+      }
+
+      const char *s;
+      for (s = out + (out_sz ? out_sz - 1 : 0); s > out && *s == trim; --s);
+
+      const size_t to_write = (size_t)(s - out);
+      if (fwrite(out, 1, to_write, stdout) != to_write)
+         err(EXIT_FAILURE, "fwrite");
+
+      memmove(out, s, (out_sz = out_sz - to_write));
+   }
+
+   free(out);
+   return EXIT_SUCCESS;
+}