record: skip whitespaces after shebang for scripts

Python tracing won't work when the shebang line has a space like below:

" #! /usr/bin/env python3 "

This patch makes uftrace to understand the above shebang as well.

Fixed: #1690

Signed-off-by: Gabriel Kim <0xgabriel.kim@gmail.com>

cmds/record.c

@@ -1625,7 +1625,7 @@ static void check_binary(struct uftrace_opts *opts)
 		if (!opts->force && !opts->patch)
 			pr_err_ns(SCRIPT_MSG, opts->exename);
 
-		script = str_ltrim(script);
+		script = str_trim(script);
 
 		/* ignore options */
 		p = strchr(script, ' ');
@@ -2188,7 +2188,7 @@ int do_child_exec(int ready, struct uftrace_opts *opts, int argc, char *argv[])
 		if (strstr(shebang, "python"))
 			is_python = true;
 #endif
-		s = str_ltrim(shebang);
+		s = str_trim(shebang);
 
 		p = strchr(s, ' ');
 		if (p != NULL)

utils/utils.c

@@ -594,6 +594,22 @@ char *strjoin(char *left, char *right, const char *delim)
 	return new;
 }
 
+/**
+ * str_trim - to trim all spaces
+ * @str: input string
+ *
+ * This function make @str to all trimmed @str
+ */
+char *str_trim(char *str)
+{
+	if (!str)
+		return NULL;
+	str = str_ltrim(str);
+	str = str_rtrim(str);
+	str = str_mtrim(str);
+	return str;
+}
+
 /**
  * str_ltrim - to trim left spaces
  * @str: input string
@@ -625,6 +641,39 @@ char *str_rtrim(char *str)
 	return str;
 }
 
+/**
+ * str_mtrim - to trim middle spaces
+ * @str: input string
+ *
+ * This function make @str to middle trimmed @str
+ */
+char *str_mtrim(char *str)
+{
+	if (!str)
+		return NULL;
+
+	char *read_ptr = str;
+	char *write_ptr = str;
+	int space_flag = 0;
+
+	while (*read_ptr != '\0') {
+		if (isspace((unsigned char)*read_ptr)) {
+			if (!space_flag) {
+				*write_ptr++ = ' ';
+				space_flag = 1;
+			}
+		}
+		else {
+			*write_ptr++ = *read_ptr;
+			space_flag = 0;
+		}
+		read_ptr++;
+	}
+
+	*write_ptr = '\0';
+	return str;
+}
+
 /**
  * strv_split - split given string and construct a string vector
  * @strv:  string vector

utils/utils.h

@@ -389,8 +389,10 @@ void strv_append(struct strv *strv, const char *str);
 void strv_replace(struct strv *strv, int idx, const char *str);
 char *strv_join(struct strv *strv, const char *delim);
 void strv_free(struct strv *strv);
+char *str_trim(char *str);
 char *str_ltrim(char *str);
 char *str_rtrim(char *str);
+char *str_mtrim(char *str);
 
 char **parse_cmdline(char *cmd, int *argc);
 void free_parsed_cmdline(char **argv);