From 8d25ce1f541d2e90c6c5ffd21d2b496a41028441 Mon Sep 17 00:00:00 2001
From: Ben Kibbey <bjk@luxsci.net>
Date: Mon, 18 Jun 2012 22:36:01 -0400
Subject: [PATCH] pwmc: add --prefix option to the .read command.

Can be used for example to specify an element path:

pwm> .read --prefix "some\telement\tpath\t" /path/to/data STORE

Easier than having to store the element path in the file.
---
 src/pwmc.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 75 insertions(+), 8 deletions(-)

diff --git a/src/pwmc.c b/src/pwmc.c
index e56b2202..e68bb66c 100644
--- a/src/pwmc.c
+++ b/src/pwmc.c
@@ -629,8 +629,14 @@ static gpg_error_t set_inquire(int fd, const char *line,
     if (line) {
 	char *s = escape(line);
 
+	if (!s) {
+	    pwmd_free(inq.line);
+	    return GPG_ERR_ENOMEM;
+	}
+
 	if (strlen(s) >= ASSUAN_LINELENGTH) {
 	    pwmd_free(inq.line);
+	    pwmd_free(s);
 	    return GPG_ERR_LINE_TOO_LONG;
 	}
 
@@ -697,20 +703,80 @@ static char *parse_arg(const char *src, char *dst, size_t len)
 	*p++ = *s;
 
     *p = 0;
-    p = dst;
-    return p;
+    return dst;
+}
+
+static char *parse_opt(char **line, const char *opt, gpg_error_t *rc)
+{
+    static char result[ASSUAN_LINELENGTH] = {0}, *r = result;
+    size_t len = 0;
+    char *s = strstr(*line, opt);
+
+    *rc = 0;
+    result[0] = 0;
+    r = result;
+
+    if (s) {
+	int quote = 0;
+	size_t rlen = strlen(opt);
+	char *p = s+rlen;
+	int lastc = 0;
+
+	while (*p && *p == ' ') {
+	    rlen++;
+	    p++;
+	}
+
+	for (; *p && len < sizeof(result)-1; p++, rlen++) {
+	    if (isspace(*p) && !quote)
+		break;
+
+	    if (*p == '\"' && lastc != '\\') {
+		quote = !quote;
+		lastc = *p;
+		continue;
+	    }
+
+	    *r++ = lastc = *p;
+	    len++;
+	}
+
+	*r = 0;
+
+	if (len >= sizeof(result)-1)
+	    *rc = GPG_ERR_LINE_TOO_LONG;
+	else {
+	    p = s+rlen;
+
+	    while (*p && *p == ' ')
+		p++;
+
+	    *line = p;
+	}
+    }
+
+    return result;
 }
 
 static gpg_error_t read_command(const char *line, char **result, size_t *len)
 {
-    const char *p = line;
     int fd;
-    gpg_error_t rc = GPG_ERR_SYNTAX;
+    gpg_error_t rc = 0;
     char filebuf[ASSUAN_LINELENGTH];
     char *filename = NULL;
     struct inquire_s *inq = NULL;
+    char *p = (char *)line;
+    const char *prefix = parse_opt(&p, "--prefix", &rc);
+
+    if (rc)
+	return rc;
+
+    rc = GPG_ERR_SYNTAX;
+
+    if (p && *p) {
+	while (*p && isspace(*p))
+	    p++;
 
-    if (p && *p && *++p) {
 	filename = parse_arg(p, filebuf, sizeof(filebuf));
 	if (filename && *filename) {
 	    p += strlen(filename)+1;
@@ -724,7 +790,8 @@ static gpg_error_t read_command(const char *line, char **result, size_t *len)
     }
 
     if (rc) {
-	fprintf(stderr, N_("Usage: .read <filename> <command> [args]\n"));
+	fprintf(stderr, N_("Usage: .read [--prefix <string>] <filename> <command> [args]\n"));
+	fprintf(stderr, N_("Use '\\' to escape special characters in the --prefix (\\t = TAB, \\\" = \")\n"));
 	return rc;
     }
 
@@ -732,7 +799,7 @@ static gpg_error_t read_command(const char *line, char **result, size_t *len)
     if (fd == -1)
 	return gpg_error_from_syserror();
 
-    rc = set_inquire(fd, NULL, &inq);
+    rc = set_inquire(fd, prefix && *prefix ? prefix : NULL, &inq);
     if (rc) {
 	close(fd);
 	return rc;
@@ -808,7 +875,7 @@ static gpg_error_t help_command(const char *line)
 		"  .open <filename>\n"
 		"      open the specified filename losing any changes to the current one\n"
 		"\n"
-		"  .read <filename> <command> [args]\n"
+		"  .read [--prefix <string>] <filename> <command> [args]\n"
 		"      obtain data from the specified filename for an inquire command\n"
 		"\n"
 		"  .set help | <name> [<value>]\n"
-- 
2.11.4.GIT