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: namhyung#1690
Signed-off-by: Yi Hong <[email protected]>

cmds/record.c

@@ -1608,7 +1608,7 @@ static void check_binary(struct uftrace_opts *opts)
 		pr_err("Cannot read '%s'", opts->exename);
 
 	if (memcmp(elf_ident, ELFMAG, SELFMAG)) {
-		char *script = check_script_file(opts->exename);
+		char *script = str_ltrim(check_script_file(opts->exename));
 		char *p;
 
 		if (script == NULL)

utils/utils.c

@@ -594,6 +594,37 @@ char *strjoin(char *left, char *right, const char *delim)
 	return new;
 }
 
+/**
+ * str_ltrim - to trim left spaces
+ * @str: input string
+ *
+ * This function make @str to left trimmed @str
+ */
+char *str_ltrim(char *str)
+{
+	if (!str)
+		return NULL;
+	while (isspace((unsigned char)*str)) {
+		str++;
+	}
+	return str;
+}
+
+/**
+ * str_rtrim - to trim right spaces
+ * @str: input string
+ *
+ * This function make @str to right trimmed @str
+ */
+char *str_rtrim(char *str)
+{
+	char *p = strchr(str, '\0');
+	while (--p >= str && isspace(*p))
+		;
+	*(p + 1) = '\0';
+	return str;
+}
+
 /**
  * strv_split - split given string and construct a string vector
  * @strv:  string vector

utils/utils.h

@@ -389,6 +389,8 @@ 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_ltrim(char *str);
+char *str_rtrim(char *str);
 
 char **parse_cmdline(char *cmd, int *argc);
 void free_parsed_cmdline(char **argv);