Update documentation. Fix bugs.

README.org

@@ -18,7 +18,7 @@
   The ctlseqs library provides low-level C API for manipulating terminal
   emulators with control sequences.
 
-  This library is free software. you can redistribute it and/or modify it
+  Ctlseqs is free software. you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by the
   Free Software Foundation, either version 3 of the License, or (at your
   option) any later version.

configure.ac

@@ -41,8 +41,6 @@ AC_TYPE_SIZE_T
 AC_TYPE_SSIZE_T
 
 # Checks for library functions.
-AC_FUNC_MALLOC
-AC_FUNC_REALLOC
 AC_CHECK_FUNCS([dprintf memset strtoul])
 
 AC_CONFIG_FILES([Makefile man/Makefile src/Makefile tests/Makefile examples/Makefile])

man/ctlseqs_read.3

@@ -51,6 +51,7 @@ A control sequence is successfully read, but fails to match any pattern in
 .TP
 .B CTLSEQS_PARTIAL
 Data is read successfully and can be recognized as part of a control sequence, but is not yet terminated.
+Partial sequence is not consumed from the read buffer.
 .TP
 .B CTLSEQS_NOSEQ
 Data is read successfully, but cannot be recognized as a valid control sequence.
@@ -60,6 +61,11 @@ The specified
 .I timeout
 has expired, and no data is read.
 .TP
+.B CTLSEQS_NOMEM
+Like
+.BR CTLSEQS_PARTIAL ,
+but the internal read buffer is full, and no data can be further read.
+.TP
 .B CTLSEQS_EOF
 End-of-file is encountered, and no data is read.
 .TP

src/ctlseqs.c

@@ -162,8 +162,8 @@ ctlseqs_poll(struct pollfd *pollfd, int timeout)
 CTLSEQS_HOT static inline int
 ctlseqs_do_read(struct ctlseqs_reader *reader)
 {
-    char *buf = reader->rbuf + reader->buf_start + reader->last_idx;
-    ssize_t nbytes = read(reader->pollfd.fd, buf, reader->readlen - reader->buf_start);
+    size_t offset = reader->buf_start + reader->last_idx;
+    ssize_t nbytes = read(reader->pollfd.fd, reader->rbuf + offset, reader->readlen - offset);
     if (CTLSEQS_UNLIKELY(nbytes == -1)) {
         if (errno == EAGAIN || errno == EWOULDBLOCK) {
             return CTLSEQS_TIMEOUT;
@@ -331,6 +331,7 @@ ctlseqs_match(struct ctlseqs_reader *reader, struct ctlseqs_matcher const *match
     for (idx = reader->last_idx; idx < len; ++idx) {
         state = ctlseqs_state_transition(state, buf[idx]);
         if (state == ctlseqs_state_err) {
+            // Anything before next ESC is definitely not a control sequence.
             for (; idx < len; ++idx) {
                 if (buf[idx] == 0x1b) {
                     break;
@@ -341,24 +342,39 @@ ctlseqs_match(struct ctlseqs_reader *reader, struct ctlseqs_matcher const *match
         }
         if (state == ctlseqs_state_done) {
             retval = ctlseqs_match_pattern(reader, matcher);
+            ++idx;
             break;
         }
     }
-    reader->state = state >= ctlseqs_state_done ? ctlseqs_state_none : state;
-    if (retval == CTLSEQS_NOMATCH || retval == CTLSEQS_PARTIAL || retval == CTLSEQS_NOSEQ) {
+    if (retval < 0) {
         reader->buffer[0].num = idx;
         reader->buffer[1].str = buf;
     }
     if (retval == CTLSEQS_PARTIAL) {
         reader->last_idx = idx;
+        if (CTLSEQS_UNLIKELY(reader->buf_start + idx == reader->readlen)) {
+            // Buffer is full but a match is still pending.
+            // This may happen when the reader's maxlen option is not large enough to hold a sequence,
+            // or when the the sequences are produced faster than consumed.
+            if (reader->buf_start > reader->readlen / 2) {
+                memcpy(reader->rbuf, reader->rbuf + reader->buf_start, idx);
+                reader->buf_start = 0;
+                reader->buf_end = idx;
+            } else {
+                // We could memmove() here, but having a buffer no larger than twice the size of a sequence
+                // is hardly what a normal program would desire.
+                retval = CTLSEQS_NOMEM;
+            }
+        }
     } else {
         reader->buf_start += idx;
         reader->last_idx = 0;
+        if (reader->buf_start == reader->buf_end) {
+            reader->buf_start = 0;
+            reader->buf_end = 0;
+        }
     }
-    if (reader->buf_start == reader->buf_end) {
-        reader->buf_start = 0;
-        reader->buf_end = 0;
-    }
+    reader->state = state >= ctlseqs_state_done ? ctlseqs_state_none : state;
     return retval;
 }
 
@@ -459,14 +475,10 @@ ctlseqs_reader_setopt(struct ctlseqs_reader *reader, struct ctlseqs_reader_opts
     size_t readlen = options->maxlen;
     if (reader->readlen != readlen) {
         char *rbuf;
-        if (reader->rbuf == NULL) {
-            rbuf = malloc(readlen);
-        } else {
-            if (readlen < reader->buf_end) {
-                return CTLSEQS_ERROR;
-            }
-            rbuf = realloc(reader->rbuf, readlen);
+        if (readlen < reader->buf_end) {
+            return CTLSEQS_ERROR;
         }
+        rbuf = realloc(reader->rbuf, readlen);
         if (rbuf == NULL) {
             return CTLSEQS_NOMEM;
         }

tests/tcsgrep.c

@@ -381,7 +381,7 @@ main(int argc, char **argv)
                 printf("TIMEOUT\n");
                 break;
             case CTLSEQS_INTR:
-                printf("INTERRUPTED\n");
+                printf("INTR\n");
                 break;
             case CTLSEQS_EOF:
                 printf("EOF\n");