diff options
| -rw-r--r-- | compat/terminal.c | 73 |
1 files changed, 72 insertions, 1 deletions
diff --git a/compat/terminal.c b/compat/terminal.c index b7f58d1781..35bca03d14 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) |