- djm@cvs.openbsd.org 2010/01/04 02:03:57

     [sftp.c]
     Implement tab-completion of commands, local and remote filenames for sftp.
     Hacked on and off for some time by myself, mouring, Carlos Silva (via 2009
     Google Summer of Code) and polished to a fine sheen by myself again.
     It should deal more-or-less correctly with the ikky corner-cases presented
     by quoted filenames, but the UI could still be slightly improved.
     In particular, it is quite slow for remote completion on large directories.
     bz#200; ok markus@

2 files changed, 443 insertions, 50 deletions

diff --git a/ChangeLog b/ChangeLog
index ac3ca7b02..70e3c15e9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -141,6 +141,15 @@
      [sshconnect2.c]
      Don't escape backslashes in the SSH2 banner.  bz#1533, patch from
      Michal Gorny via Gentoo.
+   - djm@cvs.openbsd.org 2010/01/04 02:03:57
+     [sftp.c]
+     Implement tab-completion of commands, local and remote filenames for sftp.
+     Hacked on and off for some time by myself, mouring, Carlos Silva (via 2009
+     Google Summer of Code) and polished to a fine sheen by myself again.
+     It should deal more-or-less correctly with the ikky corner-cases presented
+     by quoted filenames, but the UI could still be slightly improved.
+     In particular, it is quite slow for remote completion on large directories.
+     bz#200; ok markus@
 
 20091226
  - (tim) [contrib/cygwin/Makefile] Install ssh-copy-id and ssh-copy-id.1
diff --git a/sftp.c b/sftp.c
index d8728cc25..6a5ccc49d 100644
--- a/sftp.c
+++ b/sftp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp.c,v 1.115 2009/12/20 07:28:36 guenther Exp $ */
+/* $OpenBSD: sftp.c,v 1.116 2010/01/04 02:03:57 djm Exp $ */
 /*
  * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org>
  *
@@ -95,6 +95,12 @@ volatile sig_atomic_t interrupted = 0;
 /* I wish qsort() took a separate ctx for the comparison function...*/
 int sort_flag;
 
+/* Context used for commandline completion */
+struct complete_ctx {
+        struct sftp_conn *conn;
+        char **remote_pathp;
+};
+
 int remote_glob(struct sftp_conn *, const char *, int,
     int (*)(const char *, int), glob_t *); /* proto for sftp-glob.c */
 
@@ -145,43 +151,47 @@ extern char *__progname;
 struct CMD {
         const char *c;
         const int n;
+        const int t;
 };
 
+/* Type of completion */
+#define NOARGS  0
+#define REMOTE  1
+#define LOCAL   2
+
 static const struct CMD cmds[] = {
-        { "bye",        I_QUIT },
-        { "cd",         I_CHDIR },
-        { "chdir",      I_CHDIR },
-        { "chgrp",      I_CHGRP },
-        { "chmod",      I_CHMOD },
-        { "chown",      I_CHOWN },
-        { "df",         I_DF },
-        { "dir",        I_LS },
-        { "exit",       I_QUIT },
-        { "get",        I_GET },
-        { "mget",       I_GET },
-        { "help",       I_HELP },
-        { "lcd",        I_LCHDIR },
-        { "lchdir",     I_LCHDIR },
-        { "lls",        I_LLS },
-        { "lmkdir",     I_LMKDIR },
-        { "ln",         I_SYMLINK },
-        { "lpwd",       I_LPWD },
-        { "ls",         I_LS },
-        { "lumask",     I_LUMASK },
-        { "mkdir",      I_MKDIR },
-        { "progress",   I_PROGRESS },
-        { "put",        I_PUT },
-        { "mput",       I_PUT },
-        { "pwd",        I_PWD },
-        { "quit",       I_QUIT },
-        { "rename",     I_RENAME },
-        { "rm",         I_RM },
-        { "rmdir",      I_RMDIR },
-        { "symlink",    I_SYMLINK },
-        { "version",    I_VERSION },
-        { "!",          I_SHELL },
-        { "?",          I_HELP },
-        { NULL,                 -1}
+        { "bye",        I_QUIT,         NOARGS  },
+        { "cd",         I_CHDIR,        REMOTE  },
+        { "chdir",      I_CHDIR,        REMOTE  },
+        { "chgrp",      I_CHGRP,        REMOTE  },
+        { "chmod",      I_CHMOD,        REMOTE  },
+        { "chown",      I_CHOWN,        REMOTE  },
+        { "df",         I_DF,           REMOTE  },
+        { "dir",        I_LS,           REMOTE  },
+        { "exit",       I_QUIT,         NOARGS  },
+        { "get",        I_GET,          REMOTE  },
+        { "help",       I_HELP,         NOARGS  },
+        { "lcd",        I_LCHDIR,       LOCAL   },
+        { "lchdir",     I_LCHDIR,       LOCAL   },
+        { "lls",        I_LLS,          LOCAL   },
+        { "lmkdir",     I_LMKDIR,       LOCAL   },
+        { "ln",         I_SYMLINK,      REMOTE  },
+        { "lpwd",       I_LPWD,         LOCAL   },
+        { "ls",         I_LS,           REMOTE  },
+        { "lumask",     I_LUMASK,       NOARGS  },
+        { "mkdir",      I_MKDIR,        REMOTE  },
+        { "progress",   I_PROGRESS,     NOARGS  },
+        { "put",        I_PUT,          LOCAL   },
+        { "pwd",        I_PWD,          REMOTE  },
+        { "quit",       I_QUIT,         NOARGS  },
+        { "rename",     I_RENAME,       REMOTE  },
+        { "rm",         I_RM,           REMOTE  },
+        { "rmdir",      I_RMDIR,        REMOTE  },
+        { "symlink",    I_SYMLINK,      REMOTE  },
+        { "version",    I_VERSION,      NOARGS  },
+        { "!",          I_SHELL,        NOARGS  },
+        { "?",          I_HELP,         NOARGS  },
+        { NULL,         -1,             -1      }
 };
 
 int interactive_loop(struct sftp_conn *, char *file1, char *file2);
@@ -932,12 +942,23 @@ undo_glob_escape(char *s)
  * Split a string into an argument vector using sh(1)-style quoting,
  * comment and escaping rules, but with some tweaks to handle glob(3)
  * wildcards.
+ * The "sloppy" flag allows for recovery from missing terminating quote, for
+ * use in parsing incomplete commandlines during tab autocompletion.
+ *
  * Returns NULL on error or a NULL-terminated array of arguments.
+ *
+ * If "lastquote" is not NULL, the quoting character used for the last
+ * argument is placed in *lastquote ("\0", "'" or "\"").
+ * 
+ * If "terminated" is not NULL, *terminated will be set to 1 when the
+ * last argument's quote has been properly terminated or 0 otherwise.
+ * This parameter is only of use if "sloppy" is set.
  */
 #define MAXARGS         128
 #define MAXARGLEN       8192
 static char **
-makeargv(const char *arg, int *argcp)
+makeargv(const char *arg, int *argcp, int sloppy, char *lastquote,
+    u_int *terminated)
 {
         int argc, quot;
         size_t i, j;
@@ -951,6 +972,10 @@ makeargv(const char *arg, int *argcp)
                 error("string too long");
                 return NULL;
         }
+        if (terminated != NULL)
+                *terminated = 1;
+        if (lastquote != NULL)
+                *lastquote = '\0';
         state = MA_START;
         i = j = 0;
         for (;;) {
@@ -967,6 +992,8 @@ makeargv(const char *arg, int *argcp)
                         if (state == MA_START) {
                                 argv[argc] = argvs + j;
                                 state = q;
+                                if (lastquote != NULL)
+                                        *lastquote = arg[i];
                         } else if (state == MA_UNQUOTED) 
                                 state = q;
                         else if (state == q)
@@ -1003,6 +1030,8 @@ makeargv(const char *arg, int *argcp)
                                 if (state == MA_START) {
                                         argv[argc] = argvs + j;
                                         state = MA_UNQUOTED;
+                                        if (lastquote != NULL)
+                                                *lastquote = '\0';
                                 }
                                 if (arg[i + 1] == '?' || arg[i + 1] == '[' ||
                                     arg[i + 1] == '*' || arg[i + 1] == '\\') {
@@ -1028,6 +1057,12 @@ makeargv(const char *arg, int *argcp)
                                 goto string_done;
                 } else if (arg[i] == '\0') {
                         if (state == MA_SQUOTE || state == MA_DQUOTE) {
+                                if (sloppy) {
+                                        state = MA_UNQUOTED;
+                                        if (terminated != NULL)
+                                                *terminated = 0;
+                                        goto string_done;
+                                }
                                 error("Unterminated quoted argument");
                                 return NULL;
                         }
@@ -1041,6 +1076,8 @@ makeargv(const char *arg, int *argcp)
                         if (state == MA_START) {
                                 argv[argc] = argvs + j;
                                 state = MA_UNQUOTED;
+                                if (lastquote != NULL)
+                                        *lastquote = '\0';
                         }
                         if ((state == MA_SQUOTE || state == MA_DQUOTE) &&
                             (arg[i] == '?' || arg[i] == '[' || arg[i] == '*')) {
@@ -1063,8 +1100,8 @@ makeargv(const char *arg, int *argcp)
 }
 
 static int
-parse_args(const char **cpp, int *pflag, int *rflag, int *lflag, int *iflag, int *hflag,
-    unsigned long *n_arg, char **path1, char **path2)
+parse_args(const char **cpp, int *pflag, int *rflag, int *lflag, int *iflag,
+    int *hflag, unsigned long *n_arg, char **path1, char **path2)
 {
         const char *cmd, *cp = *cpp;
         char *cp2, **argv;
@@ -1086,7 +1123,7 @@ parse_args(const char **cpp, int *pflag, int *rflag, int *lflag, int *iflag, int
                 cp++;
         }
 
-        if ((argv = makeargv(cp, &argc)) == NULL)
+        if ((argv = makeargv(cp, &argc, 0, NULL, NULL)) == NULL)
                 return -1;
 
         /* Figure out which command we have */
@@ -1468,10 +1505,344 @@ prompt(EditLine *el)
 }
 #endif
 
+/* Display entries in 'list' after skipping the first 'len' chars */
+static void
+complete_display(char **list, u_int len)
+{
+        u_int y, m = 0, width = 80, columns = 1, colspace = 0, llen;
+        struct winsize ws;
+        char *tmp;
+
+        /* Count entries for sort and find longest */
+        for (y = 0; list[y]; y++) 
+                m = MAX(m, strlen(list[y]));
+
+        if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) != -1)
+                width = ws.ws_col;
+
+        m = m > len ? m - len : 0;
+        columns = width / (m + 2);
+        columns = MAX(columns, 1);
+        colspace = width / columns;
+        colspace = MIN(colspace, width);
+
+        printf("\n");
+        m = 1;
+        for (y = 0; list[y]; y++) {
+                llen = strlen(list[y]);
+                tmp = llen > len ? list[y] + len : "";
+                printf("%-*s", colspace, tmp);
+                if (m >= columns) {
+                        printf("\n");
+                        m = 1;
+                } else
+                        m++;
+        }
+        printf("\n");
+}
+
+/*
+ * Given a "list" of words that begin with a common prefix of "word",
+ * attempt to find an autocompletion to extends "word" by the next
+ * characters common to all entries in "list".
+ */
+static char *
+complete_ambiguous(const char *word, char **list, size_t count)
+{
+        if (word == NULL)
+                return NULL;
+
+        if (count > 0) {
+                u_int y, matchlen = strlen(list[0]);
+
+                /* Find length of common stem */
+                for (y = 1; list[y]; y++) {
+                        u_int x;
+
+                        for (x = 0; x < matchlen; x++) 
+                                if (list[0][x] != list[y][x]) 
+                                        break;
+
+                        matchlen = x;
+                }
+
+                if (matchlen > strlen(word)) {
+                        char *tmp = xstrdup(list[0]);
+
+                        tmp[matchlen] = NULL;
+                        return tmp;
+                }
+        } 
+
+        return xstrdup(word);
+}
+
+/* Autocomplete a sftp command */
+static int
+complete_cmd_parse(EditLine *el, char *cmd, int lastarg, char quote,
+    int terminated)
+{
+        u_int y, count = 0, cmdlen, tmplen;
+        char *tmp, **list, argterm[3];
+        const LineInfo *lf;
+
+        list = xcalloc((sizeof(cmds) / sizeof(*cmds)) + 1, sizeof(char *));
+
+        /* No command specified: display all available commands */
+        if (cmd == NULL) {
+                for (y = 0; cmds[y].c; y++)
+                        list[count++] = xstrdup(cmds[y].c);
+                
+                list[count] = NULL;
+                complete_display(list, 0);
+
+                for (y = 0; list[y] != NULL; y++)  
+                        xfree(list[y]); 
+                xfree(list);
+                return count;
+        }
+
+        /* Prepare subset of commands that start with "cmd" */
+        cmdlen = strlen(cmd);
+        for (y = 0; cmds[y].c; y++)  {
+                if (!strncasecmp(cmd, cmds[y].c, cmdlen)) 
+                        list[count++] = xstrdup(cmds[y].c);
+        }
+        list[count] = NULL;
+
+        if (count == 0)
+                return 0;
+
+        /* Complete ambigious command */
+        tmp = complete_ambiguous(cmd, list, count);
+        if (count > 1)
+                complete_display(list, 0);
+
+        for (y = 0; list[y]; y++)  
+                xfree(list[y]); 
+        xfree(list);
+
+        if (tmp != NULL) {
+                tmplen = strlen(tmp);
+                cmdlen = strlen(cmd);
+                /* If cmd may be extended then do so */
+                if (tmplen > cmdlen)
+                        if (el_insertstr(el, tmp + cmdlen) == -1)
+                                fatal("el_insertstr failed.");
+                lf = el_line(el);
+                /* Terminate argument cleanly */
+                if (count == 1) {
+                        y = 0;
+                        if (!terminated)
+                                argterm[y++] = quote;
+                        if (lastarg || *(lf->cursor) != ' ')
+                                argterm[y++] = ' ';
+                        argterm[y] = '\0';
+                        if (y > 0 && el_insertstr(el, argterm) == -1)
+                                fatal("el_insertstr failed.");
+                }
+                xfree(tmp);
+        }
+
+        return count;
+}
+
+/*
+ * Determine whether a particular sftp command's arguments (if any)
+ * represent local or remote files.
+ */
+static int
+complete_is_remote(char *cmd) {
+        int i;
+
+        if (cmd == NULL)
+                return -1;
+
+        for (i = 0; cmds[i].c; i++) {
+                if (!strncasecmp(cmd, cmds[i].c, strlen(cmds[i].c))) 
+                        return cmds[i].t;
+        }
+
+        return -1;
+}
+
+/* Autocomplete a filename "file" */
+static int
+complete_match(EditLine *el, struct sftp_conn *conn, char *remote_path,
+    char *file, int remote, int lastarg, char quote, int terminated)
+{
+        glob_t g;
+        char *tmp, *tmp2, ins[3];
+        u_int i, hadglob, pwdlen, len, tmplen, filelen;
+        const LineInfo *lf;
+        
+        /* Glob from "file" location */
+        if (file == NULL)
+                tmp = xstrdup("*");
+        else
+                xasprintf(&tmp, "%s*", file);
+
+        memset(&g, 0, sizeof(g));
+        if (remote != LOCAL) {
+                tmp = make_absolute(tmp, remote_path);
+                remote_glob(conn, tmp, GLOB_DOOFFS|GLOB_MARK, NULL, &g);
+        } else 
+                glob(tmp, GLOB_DOOFFS|GLOB_MARK, NULL, &g);
+        
+        /* Determine length of pwd so we can trim completion display */
+        for (hadglob = tmplen = pwdlen = 0; tmp[tmplen] != 0; tmplen++) {
+                /* Terminate counting on first unescaped glob metacharacter */
+                if (tmp[tmplen] == '*' || tmp[tmplen] == '?') {
+                        if (tmp[tmplen] != '*' || tmp[tmplen + 1] != '\0')
+                                hadglob = 1;
+                        break;
+                }
+                if (tmp[tmplen] == '\\' && tmp[tmplen + 1] != '\0')
+                        tmplen++;
+                if (tmp[tmplen] == '/')
+                        pwdlen = tmplen + 1;    /* track last seen '/' */
+        }
+        xfree(tmp);
+
+        if (g.gl_matchc == 0) 
+                goto out;
+
+        if (g.gl_matchc > 1)
+                complete_display(g.gl_pathv, pwdlen);
+
+        tmp = NULL;
+        /* Don't try to extend globs */
+        if (file == NULL || hadglob)
+                goto out;
+
+        tmp2 = complete_ambiguous(file, g.gl_pathv, g.gl_matchc);
+        tmp = path_strip(tmp2, remote_path);
+        xfree(tmp2);
+
+        if (tmp == NULL)
+                goto out;
+
+        tmplen = strlen(tmp);
+        filelen = strlen(file);
+
+        if (tmplen > filelen)  {
+                tmp2 = tmp + filelen;
+                len = strlen(tmp2); 
+                /* quote argument on way out */
+                for (i = 0; i < len; i++) {
+                        ins[0] = '\\';
+                        ins[1] = tmp2[i];
+                        ins[2] = '\0';
+                        switch (tmp2[i]) {
+                        case '\'':
+                        case '"':
+                        case '\\':
+                        case '\t':
+                        case ' ':
+                                if (quote == '\0' || tmp2[i] == quote) {
+                                        if (el_insertstr(el, ins) == -1)
+                                                fatal("el_insertstr "
+                                                    "failed.");
+                                        break;
+                                }
+                                /* FALLTHROUGH */
+                        default:
+                                if (el_insertstr(el, ins + 1) == -1)
+                                        fatal("el_insertstr failed.");
+                                break;
+                        }
+                }
+        }
+
+        lf = el_line(el);
+        /*
+         * XXX should we really extend here? the user may not be done if
+         * the filename is a directory.
+         */
+        if (g.gl_matchc == 1) {
+                i = 0;
+                if (!terminated)
+                        ins[i++] = quote;
+                if (lastarg || *(lf->cursor) != ' ')
+                        ins[i++] = ' ';
+                ins[i] = '\0';
+                if (i > 0 && el_insertstr(el, ins) == -1)
+                        fatal("el_insertstr failed.");
+        }
+        xfree(tmp);
+
+ out:
+        globfree(&g);
+        return g.gl_matchc;
+}
+
+/* tab-completion hook function, called via libedit */
+static unsigned char
+complete(EditLine *el, int ch)
+{
+        char **argv, *line, quote; 
+        u_int argc, carg, cursor, len, terminated, ret = CC_ERROR;
+        const LineInfo *lf;
+        struct complete_ctx *complete_ctx;
+
+        lf = el_line(el);
+        if (el_get(el, EL_CLIENTDATA, (void**)&complete_ctx) != 0)
+                fatal("%s: el_get failed", __func__);
+
+        /* Figure out which argument the cursor points to */
+        cursor = lf->cursor - lf->buffer;
+        line = (char *)xmalloc(cursor + 1);
+        memcpy(line, lf->buffer, cursor);
+        line[cursor] = '\0';
+        argv = makeargv(line, &carg, 1, &quote, &terminated);
+        xfree(line);
+
+        /* Get all the arguments on the line */
+        len = lf->lastchar - lf->buffer;
+        line = (char *)xmalloc(len + 1);
+        memcpy(line, lf->buffer, len);
+        line[len] = '\0';
+        argv = makeargv(line, &argc, 1, NULL, NULL);
+
+        /* Ensure cursor is at EOL or a argument boundary */
+        if (line[cursor] != ' ' && line[cursor] != '\0' &&
+            line[cursor] != '\n') {
+                xfree(line);
+                return ret;
+        }
+
+        if (carg == 0) {
+                /* Show all available commands */
+                complete_cmd_parse(el, NULL, argc == carg, '\0', 1);
+                ret = CC_REDISPLAY;
+        } else if (carg == 1 && cursor > 0 && line[cursor - 1] != ' ')  {
+                /* Handle the command parsing */
+                if (complete_cmd_parse(el, argv[0], argc == carg,
+                    quote, terminated) != 0) 
+                        ret = CC_REDISPLAY;
+        } else if (carg >= 1) {
+                /* Handle file parsing */
+                int remote = complete_is_remote(argv[0]);
+                char *filematch = NULL;
+
+                if (carg > 1 && line[cursor-1] != ' ')
+                        filematch = argv[carg - 1];
+
+                if (remote != 0 &&
+                    complete_match(el, complete_ctx->conn,
+                    *complete_ctx->remote_pathp, filematch,
+                    remote, carg == argc, quote, terminated) != 0) 
+                        ret = CC_REDISPLAY;
+        }
+
+        xfree(line);    
+        return ret;
+}
+
 int
 interactive_loop(struct sftp_conn *conn, char *file1, char *file2)
 {
-        char *pwd;
+        char *remote_path;
         char *dir = NULL;
         char cmd[2048];
         int err, interactive;
@@ -1480,6 +1851,7 @@ interactive_loop(struct sftp_conn *conn, char *file1, char *file2)
         History *hl = NULL;
         HistEvent hev;
         extern char *__progname;
+        struct complete_ctx complete_ctx;
 
         if (!batchmode && isatty(STDIN_FILENO)) {
                 if ((el = el_init(__progname, stdin, stdout, stderr)) == NULL)
@@ -1494,23 +1866,32 @@ interactive_loop(struct sftp_conn *conn, char *file1, char *file2)
                 el_set(el, EL_TERMINAL, NULL);
                 el_set(el, EL_SIGNAL, 1);
                 el_source(el, NULL);
+
+                /* Tab Completion */
+                el_set(el, EL_ADDFN, "ftp-complete", 
+                    "Context senstive argument completion", complete);
+                complete_ctx.conn = conn;
+                complete_ctx.remote_pathp = &remote_path;
+                el_set(el, EL_CLIENTDATA, (void*)&complete_ctx);
+                el_set(el, EL_BIND, "^I", "ftp-complete", NULL);
         }
 #endif /* USE_LIBEDIT */
 
-        pwd = do_realpath(conn, ".");
-        if (pwd == NULL)
+        remote_path = do_realpath(conn, ".");
+        if (remote_path == NULL)
                 fatal("Need cwd");
 
         if (file1 != NULL) {
                 dir = xstrdup(file1);
-                dir = make_absolute(dir, pwd);
+                dir = make_absolute(dir, remote_path);
 
                 if (remote_is_dir(conn, dir) && file2 == NULL) {
                         printf("Changing to: %s\n", dir);
                         snprintf(cmd, sizeof cmd, "cd \"%s\"", dir);
-                        if (parse_dispatch_command(conn, cmd, &pwd, 1) != 0) {
+                        if (parse_dispatch_command(conn, cmd,
+                            &remote_path, 1) != 0) {
                                 xfree(dir);
-                                xfree(pwd);
+                                xfree(remote_path);
                                 xfree(conn);
                                 return (-1);
                         }
@@ -1521,9 +1902,10 @@ interactive_loop(struct sftp_conn *conn, char *file1, char *file2)
                                 snprintf(cmd, sizeof cmd, "get %s %s", dir,
                                     file2);
 
-                        err = parse_dispatch_command(conn, cmd, &pwd, 1);
+                        err = parse_dispatch_command(conn, cmd,
+                            &remote_path, 1);
                         xfree(dir);
-                        xfree(pwd);
+                        xfree(remote_path);
                         xfree(conn);
                         return (err);
                 }
@@ -1564,7 +1946,8 @@ interactive_loop(struct sftp_conn *conn, char *file1, char *file2)
                         const char *line;
                         int count = 0;
 
-                        if ((line = el_gets(el, &count)) == NULL || count <= 0) {
+                        if ((line = el_gets(el, &count)) == NULL ||
+                            count <= 0) {
                                 printf("\n");
                                 break;
                         }
@@ -1584,11 +1967,12 @@ interactive_loop(struct sftp_conn *conn, char *file1, char *file2)
                 interrupted = 0;
                 signal(SIGINT, cmd_interrupt);
 
-                err = parse_dispatch_command(conn, cmd, &pwd, batchmode);
+                err = parse_dispatch_command(conn, cmd, &remote_path,
+                    batchmode);
                 if (err != 0)
                         break;
         }
-        xfree(pwd);
+        xfree(remote_path);
         xfree(conn);
 
 #ifdef USE_LIBEDIT