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-rw-r--r--compat/terminal.c73
1 files changed, 72 insertions, 1 deletions
diff --git a/compat/terminal.c b/compat/terminal.c
index b7f58d1..35bca03 100644
--- a/compat/terminal.c
+++ b/compat/terminal.c
@@ -4,6 +4,7 @@
#include "strbuf.h"
#include "run-command.h"
#include "string-list.h"
+#include "hashmap.h"
#if defined(HAVE_DEV_TTY) || defined(GIT_WINDOWS_NATIVE)
@@ -238,6 +239,71 @@ char *git_terminal_prompt(const char *prompt, int echo)
return buf.buf;
}
+/*
+ * The `is_known_escape_sequence()` function returns 1 if the passed string
+ * corresponds to an Escape sequence that the terminal capabilities contains.
+ *
+ * To avoid depending on ncurses or other platform-specific libraries, we rely
+ * on the presence of the `infocmp` executable to do the job for us (failing
+ * silently if the program is not available or refused to run).
+ */
+struct escape_sequence_entry {
+ struct hashmap_entry entry;
+ char sequence[FLEX_ARRAY];
+};
+
+static int sequence_entry_cmp(const void *hashmap_cmp_fn_data,
+ const struct escape_sequence_entry *e1,
+ const struct escape_sequence_entry *e2,
+ const void *keydata)
+{
+ return strcmp(e1->sequence, keydata ? keydata : e2->sequence);
+}
+
+static int is_known_escape_sequence(const char *sequence)
+{
+ static struct hashmap sequences;
+ static int initialized;
+
+ if (!initialized) {
+ struct child_process cp = CHILD_PROCESS_INIT;
+ struct strbuf buf = STRBUF_INIT;
+ char *p, *eol;
+
+ hashmap_init(&sequences, (hashmap_cmp_fn)sequence_entry_cmp,
+ NULL, 0);
+
+ argv_array_pushl(&cp.args, "infocmp", "-L", "-1", NULL);
+ if (pipe_command(&cp, NULL, 0, &buf, 0, NULL, 0))
+ strbuf_setlen(&buf, 0);
+
+ for (eol = p = buf.buf; *p; p = eol + 1) {
+ p = strchr(p, '=');
+ if (!p)
+ break;
+ p++;
+ eol = strchrnul(p, '\n');
+
+ if (starts_with(p, "\\E")) {
+ char *comma = memchr(p, ',', eol - p);
+ struct escape_sequence_entry *e;
+
+ p[0] = '^';
+ p[1] = '[';
+ FLEX_ALLOC_MEM(e, sequence, p, comma - p);
+ hashmap_entry_init(&e->entry,
+ strhash(e->sequence));
+ hashmap_add(&sequences, &e->entry);
+ }
+ if (!*eol)
+ break;
+ }
+ initialized = 1;
+ }
+
+ return !!hashmap_get_from_hash(&sequences, strhash(sequence), sequence);
+}
+
int read_key_without_echo(struct strbuf *buf)
{
static int warning_displayed;
@@ -271,7 +337,12 @@ int read_key_without_echo(struct strbuf *buf)
* Start by replacing the Escape byte with ^[ */
strbuf_splice(buf, buf->len - 1, 1, "^[", 2);
- for (;;) {
+ /*
+ * Query the terminal capabilities once about all the Escape
+ * sequences it knows about, so that we can avoid waiting for
+ * half a second when we know that the sequence is complete.
+ */
+ while (!is_known_escape_sequence(buf->buf)) {
struct pollfd pfd = { .fd = 0, .events = POLLIN };
if (poll(&pfd, 1, 500) < 1)