Initial commit

1 files changed, 393 insertions, 0 deletions

diff --git a/ask.c b/ask.c
new file mode 100644
index 0000000..42b7b3b
--- /dev/null
+++ b/ask.c
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+/* ask - a simple command line asker
+ * Copyright 2019 Bruce Hill
+ * Released under the MIT License (see LICENSE for details)
+ * Usage: ask [-p | --password] [-q | --quickpick] [prompt [initial value]]
+ *    -p: password mode
+ *    -q: quickpick mode (exit when only one option remains)
+ */
+#include <poll.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "bterm.h"
+
+static int password = 0, quickpick = 0, case_sensitive = 0, to_skip = 0;
+
+#define LOWERCASE(c) ('A' <= (c) && (c) <= 'Z' ? ((c) + 'a' - 'A') : (c))
+#define EQ(a, b) (case_sensitive ? (a) == (b) : LOWERCASE(a) == LOWERCASE(b))
+
+static inline void *memcheck(void *p)
+{
+    if (!p) {
+        fprintf(stderr, "Memory allocation failure\n");
+        exit(1);
+    }
+    return p;
+}
+
+static int score(const char *str, const char *patt)
+{
+    if (!patt[0]) return 0;
+    int score = 0;
+    const char *sp = str, *pp = patt;
+    while (*sp && !EQ(*sp, *pp)) ++sp;
+    while (*sp && *pp && EQ(*sp, *pp)) {
+        ++score;
+        ++sp;
+        ++pp;
+    }
+    for (; *pp; ++sp, ++pp) {
+        while (*sp && !EQ(*sp, *pp)) ++sp;
+        if (!*sp) return 0;
+    }
+    if (*pp && !*sp) return 0;
+    return score;
+}
+
+static void draw_line(FILE *out, const char *line, const char *hl, const char *cur)
+{
+    int dim = 0, backtrack = 0;
+    for (const char *pl = line, *phl = hl; *pl; pl++) {
+        if (phl >= cur) ++backtrack;
+        if (case_sensitive ? *pl == *phl : LOWERCASE(*pl) == LOWERCASE(*phl)) {
+            ++phl;
+            if (dim) {
+                fputs("\033[22m", out);
+                dim = 0;
+            }
+        } else if (!dim) {
+            fputs("\033[2m", out);
+            dim = 1;
+        }
+        fputc(*pl, out);
+    }
+    if (backtrack)
+        fprintf(out, "\033[%dD", backtrack);
+}
+
+/*
+ * A basic fuzzly matcher
+ */
+static char *fzline(FILE *in, FILE *out, const char *prompt, const char *initial, int nopts, char **opts)
+{
+    size_t cap = initial ? strlen(initial) + 100 : 100;
+    char *buf = memcheck(calloc(cap, 1));
+    char *picked = NULL;
+    int b = 0, len = 0;
+    if (initial) {
+        if (!strcpy(buf, initial)) return NULL;
+        len = (int)strlen(initial);
+        b = len;
+        fputs(initial, out);
+    }
+
+    // Show cursor and set to blinking line:
+    while (1) {
+        fputs("\033[G\033[K\033[0m", out);
+        if (prompt) {
+            fputs("\033[1G\033[K\033[37;1m", out);
+            fputs(prompt, out);
+            fputs("\033[0m", out);
+        }
+        picked = NULL;
+        case_sensitive = 0;
+        for (const char *p = buf; *p; ++p)
+            case_sensitive |= ('A' <= *p && *p <= 'Z');
+
+        int ncandidates = 0;
+        for (int i = 0; i < nopts; i++)
+            ncandidates += score(opts[i], buf) > 0;
+
+        int bestscore = 0;
+        char *best = NULL;
+        int skipped = 0;
+        for (int i = 0; i < nopts; i++) {
+            int s = score(opts[i], buf);
+            if (s && skipped < to_skip) {
+                ++skipped;
+                continue;
+            }
+            if (s > bestscore) {
+                best = opts[i];
+                bestscore = s;
+            }
+        }
+        if (quickpick && ncandidates == 1 && best)
+            return best;
+
+        picked = best;
+        if (best) {
+            draw_line(out, best, buf, &buf[b]);
+        } else {
+            fprintf(out, "\033[0;31m%s\033[0m", buf);
+            if (b < (int)strlen(buf))
+                fprintf(out, "\033[%dD", (int)strlen(buf) - b);
+        }
+        fflush(out);
+        int key;
+      skip_redraw:
+        key = bgetkey(in, NULL, NULL, -1);
+        switch (key) {
+            case -1: case -2: case -3: goto skip_redraw;
+            case '\r':
+                // TODO: support backslash-enter
+                goto finished;
+            case KEY_CTRL_C: case KEY_ESC:
+                free(buf);
+                picked = NULL;
+                goto finished;
+            case KEY_CTRL_A:
+                if (b > 0) b = 0;
+                break;
+            case KEY_CTRL_E:
+                if (b < len) b = len;
+                break;
+            case KEY_CTRL_U: {
+                int to_clear = b;
+                if (to_clear) {
+                    memmove(buf, buf+b, (size_t)(len-b));
+                    buf[len -= b] = 0;
+                    b = 0;
+                }
+                break;
+            }
+            case KEY_CTRL_K:
+                if (b < len)
+                    buf[len = b] = 0;
+                break;
+            case KEY_CTRL_N:
+                if (ncandidates)
+                    to_skip = (to_skip + 1) % ncandidates;
+                break;
+            case KEY_CTRL_P:
+                if (ncandidates)
+                    to_skip = (to_skip + ncandidates - 1) % ncandidates;
+                break;
+            case KEY_BACKSPACE: case KEY_BACKSPACE2:
+                if (b > 0) {
+                    --b;
+                    memmove(buf+b, buf+b+1, (size_t)(len-b));
+                    buf[--len] = 0;
+                }
+                break;
+            case KEY_DELETE: case KEY_CTRL_D:
+                if (b < len) {
+                    memmove(buf+b, buf+b+1, (size_t)(len-b));
+                    buf[--len] = 0;
+                }
+                break;
+            case KEY_ARROW_LEFT: case KEY_CTRL_B:
+                if (b > 0) --b;
+                break;
+            case KEY_ARROW_RIGHT: case KEY_CTRL_F:
+                if (b < len) ++b;
+                break;
+            default:
+                if (' ' <= key && key <= '~') {
+                    if (len + 1 >= (int)cap) {
+                        buf = memcheck(realloc(buf, (cap += 100)));
+                        if (!buf) goto finished;
+                    }
+                    if (b < len)
+                        memmove(buf+b+1, buf+b, (size_t)(len-b+1));
+                    buf[b++] = (char)key;
+                    buf[++len] = 0;
+                }
+                break;
+        }
+    }
+  finished:
+    return picked;
+}
+
+/**
+ * A basic readline implementation. No history, but all the normal editing
+ * key bindings like Ctrl-U to clear to the beginning of the line, backspace,
+ * arrow keys, etc.
+ *
+ * Takes an input file and output file, and an optional prompt and returns
+ * a malloc'd string containing the user's input or NULL if an error occurred
+ * or if the user hit Escape or Ctrl-c.
+ */
+static char *breadline(FILE *in, FILE *out, const char *prompt, const char *initial)
+{
+    size_t cap = initial ? strlen(initial) + 100 : 100;
+    char *buf = calloc(cap, 1);
+    if (!buf) return NULL;
+    int i = 0, len = 0;
+    if (prompt) {
+        fputs("\033[1G\033[K\033[37;1m", out);
+        fputs(prompt, out);
+        fputs("\033[0m", out);
+    }
+    if (initial) {
+        strcpy(buf, initial);
+        len = (int)strlen(initial);
+        i = len;
+        fputs(initial, out);
+    }
+    // Show cursor
+    fputs("\033[?25h", out);
+    while (1) {
+        fflush(out);
+        int key = bgetkey(in, NULL, NULL, -1);
+        switch (key) {
+            case -1: case -2: case -3: continue;
+            case '\r':
+                // TODO: support backslash-enter
+                goto finished;
+            case KEY_CTRL_C: case KEY_ESC:
+                free(buf);
+                buf = NULL;
+                goto finished;
+            case KEY_CTRL_A:
+                if (i > 0) {
+                    fprintf(out, "\033[%dD", i);
+                    i = 0;
+                }
+                break;
+            case KEY_CTRL_E:
+                if (i < len) {
+                    fprintf(out, "\033[%dC", len-i);
+                    i = len;
+                }
+                break;
+            case KEY_CTRL_U: {
+                int to_clear = i;
+                if (to_clear) {
+                    memmove(buf, buf+i, (size_t)(len-i));
+                    buf[len -= i] = 0;
+                    i = 0;
+                    fprintf(out, "\033[%dD\033[K", to_clear);
+                    if (len > 0)
+                        fprintf(out, "%s\033[%dD", buf, len);
+                }
+                break;
+            }
+            case KEY_CTRL_K:
+                if (i < len) {
+                    buf[len = i] = 0;
+                    fputs("\033[K", out);
+                }
+                break;
+            case KEY_BACKSPACE: case KEY_BACKSPACE2:
+                if (i > 0) {
+                    --i;
+                    memmove(buf+i, buf+i+1, (size_t)(len-i));
+                    buf[--len] = 0;
+                    if (i == len) fputs("\033[D \033[D", out);
+                    else fprintf(out, "\033[D%s\033[K\033[%dD", buf+i, len-i);
+                }
+                break;
+            case KEY_DELETE: case KEY_CTRL_D:
+                if (i < len) {
+                    memmove(buf+i, buf+i+1, (size_t)(len-i));
+                    buf[--len] = 0;
+                    if (i == len) fputs(" \033[D", out);
+                    else fprintf(out, "%s\033[K\033[%dD", buf+i, len-i);
+                }
+                break;
+            case KEY_ARROW_LEFT: case KEY_CTRL_B:
+                if (i > 0) {
+                    --i;
+                    fputs("\033[D", out);
+                }
+                break;
+            case KEY_ARROW_RIGHT: case KEY_CTRL_F:
+                if (i < len) {
+                    ++i;
+                    fputs("\033[C", out);
+                }
+                break;
+            default:
+                if (' ' <= key && key <= '~') {
+                    if (len + 1 >= (int)cap) {
+                        cap += 100;
+                        buf = realloc(buf, cap);
+                        if (!buf) goto finished;
+                    }
+                    if (i < len)
+                        memmove(buf+i+1, buf+i, (size_t)(len-i+1));
+                    buf[i++] = (char)key;
+                    buf[++len] = 0;
+                    if (i == len)
+                        fputc(key, out);
+                    else
+                        fprintf(out, "%c%s\033[%dD", (char)key, buf+i, len-i);
+                }
+                break;
+        }
+    }
+  finished:
+    // Reset cursor to block
+    fputs("\033[1G\033[1 q\033[2K", out);
+    return buf;
+}
+
+int main(int argc, char *argv[])
+{
+    FILE *tty_in = fopen("/dev/tty", "r");
+    FILE *tty_out = fopen("/dev/tty", "w");
+    struct termios orig_termios, bb_termios;
+    tcgetattr(fileno(tty_out), &orig_termios);
+    cfmakeraw(&bb_termios);
+    if (tcsetattr(fileno(tty_out), TCSAFLUSH, &bb_termios) == -1)
+        return 1;
+
+    char *prompt = NULL, *initial = NULL;
+    char **lines = NULL;
+    size_t linescap = 0, linecap = 0;
+    int nlines = 0;
+    char *line = NULL;
+    struct pollfd pfd = {STDIN_FILENO, POLLIN, 0};
+    if (poll(&pfd, 1, 50) > 0) {
+        while ((getline(&line, &linecap, stdin)) >= 0) {
+            if ((size_t)nlines >= linescap)
+                lines = memcheck(realloc(lines, (linescap += 100)*sizeof(char*)));
+            if (!line[0]) continue;
+            if (line[strlen(line)-1] == '\n')
+                line[strlen(line)-1] = '\0';
+            lines[nlines++] = memcheck(strdup(line));
+        }
+    }
+    int a = 1;
+    while (a < argc) {
+        if (strcmp(argv[a], "-p") == 0 || strcmp(argv[a], "--password") == 0) {
+            password = 1;
+        } else if (strcmp(argv[a], "-q") == 0 || strcmp(argv[a], "--quickpick") == 0) {
+            quickpick = 1;
+        } else break;
+        ++a;
+    }
+    if (!prompt && a < argc) prompt = argv[a++];
+    if (!initial && a < argc) initial = argv[a++];
+
+    while (a < argc) {
+        if ((size_t)nlines >= linescap)
+            lines = memcheck(realloc(lines, (linescap += 100)*sizeof(char*)));
+        lines[nlines++] = argv[a++];
+    }
+
+    char *output = nlines > 0
+        ? fzline(tty_in, tty_out, prompt, initial, nlines, lines)
+        : breadline(tty_in, tty_out, prompt, initial);
+
+    fputs("\033[G\033[K\033[0m", tty_out);
+    fflush(tty_out);
+    tcsetattr(fileno(tty_out), TCSAFLUSH, &orig_termios);
+    fclose(tty_out);
+    tty_out = NULL;
+    fclose(tty_in);
+    tty_in = NULL;
+
+    if (!output) return 1;
+
+    puts(output);
+    return 0;
+}
+// vim: ts=4 sw=0 et cino=L2,l1,(0,W4,m1