[Libguestfs] [PATCH 3/5] daemon: debug: new "exists" subcommand

Easy way to check whether a file in the appliance exists. --- daemon/debug.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/daemon/debug.c b/daemon/debug.c index c646be7..2193fe6 100644 --- a/daemon/debug.c +++ b/daemon/debug.c @@ -67,6 +67,7 @@ static char *debug_core_pattern (const char *subcmd, size_t argc, char *const *c static char *debug_device_speed (const char *subcmd, size_t argc, char *const *const argv); static char *debug_env (const char *subcmd, size_t argc, char *const *const argv); static char *debug_error (const char *subcmd, size_t argc, char *const *const argv); +static char *debug_exists (const char *subcmd, size_t argc, char *const *const argv); static char *debug_fds (const char *subcmd, size_t argc, char *const *const argv); static char *debug_ldd (const char *subcmd, size_t argc, char *const *const argv); static char *debug_ls (const char *subcmd, size_t argc, char *const *const argv); @@ -90,6 +91,7 @@ static struct cmd cmds[] = { { "device_speed", debug_device_speed }, { "env", debug_env }, { "error", debug_error }, + { "exists", debug_exists }, { "fds", debug_fds }, { "ldd", debug_ldd }, { "ls", debug_ls }, @@ -933,6 +935,43 @@ do_debug_upload (const char *filename, int mode) return 0; } +/* Check whether a file in the appliance exists. + * An empty string is returned if the file does not exist, + * an "ok" string when the file exists, and an error in case of other + * stat errors. + */ +static char * +debug_exists (const char *subcmd, size_t argc, char *const *const argv) +{ + char *ret; + int r; + struct stat buf; + + if (argc != 1) { + reply_with_error ("exists: one argument expected"); + return NULL; + } + + r = stat (argv[0], &buf); + + if (r == -1) { + if (errno != ENOENT && errno != ENOTDIR) { + reply_with_perror ("stat: %s", argv[0]); + return NULL; + } + else + ret = strdup (""); + } else + ret = strdup ("ok"); + + if (NULL == ret) { + reply_with_perror ("strdup"); + return NULL; + } + + return ret; +} + /* This function is identical to debug_upload. */ /* Has one FileIn parameter. */ int -- 2.7.4