[ltt-dev] [LTTCTL PATCH] Add getopt for options management

[Mathieu Desnoyers]

* David Goulet (david.goulet at polymtl.ca) wrote:
> This patch also introduce the usage function.

Fixed a mistake in the patch (removed the geteuid() from main).

Committed and pushed.

Thanks,

Mathieu

> 
> Signed-off-by: David Goulet <david.goulet at polymtl.ca>
> ---
>  lttng/lttngtrace.c |   79 +++++++++++++++++++++++++++++++--------------------
>  1 files changed, 48 insertions(+), 31 deletions(-)
> 
> diff --git a/lttng/lttngtrace.c b/lttng/lttngtrace.c
> index 20f8dad..37376a3 100644
> --- a/lttng/lttngtrace.c
> +++ b/lttng/lttngtrace.c
> @@ -52,6 +52,16 @@ static int autotrace;	/*
>  			 * we unlink if needed ?
>  			 */
>  static int sigfwd_pid;
> +static char *progname = NULL;
> +
> +void usage(void) {
> +	fprintf(stderr, "usage : %s [-o trace_name] command\n", progname);
> +	fprintf(stderr, "\nTracing tool for LTTng and UST\n\
> +\n\
> +Options:\n\
> +	-o trace_name\t\tOutput file of the trace\n\
> +");
> +}
>  
>  static int recunlink(const char *dirname)
>  {
> @@ -151,7 +161,7 @@ static int write_child_pid(pid_t pid, uid_t uid, gid_t gid)
>  		perror("Error writing child pid");
>  		return -errno;
>  	}
> -	
> +
>  	fprintf(fp, "%u", (unsigned int) pid);
>  	ret = fclose(fp);
>  	if (ret)
> @@ -163,32 +173,38 @@ static int write_child_pid(pid_t pid, uid_t uid, gid_t gid)
>  	return ret;
>  }
>  
> -static int parse_options(int argc, char *argv[], int *arg)
> +static int parse_options(int argc, char **argv, int *arg)
>  {
> -	int ret = 0;
> -
> -	for (;;) {
> -		if (*arg >= argc
> -		    || argv[*arg][0] != '-'
> -		    || argv[*arg][0] == '\0'
> -		    || argv[*arg][1] == '\0'
> -		    || !strcmp(argv[*arg], "--"))
> -			break;
> -		switch (argv[*arg][1]) {
> -		case 'o':	if (*arg + 1 >= argc) {
> -					printf("Missing -o trace name\n");
> -					ret = -EINVAL;
> -					break;
> -				}
> -				trace_path = argv[*arg + 1];
> -				(*arg) += 2;
> +	int i, c;
> +
> +	while ((c = getopt(argc, argv, "ho:")) != -1) {
> +		switch (c) {
> +			case 'o':
> +				trace_path = strdup(optarg);
>  				break;
> -		default:	printf("Unknown option -%c\n", argv[*arg][1]);
> -				ret = -EINVAL;
> -				return ret;
> +			case 'h':
> +				usage();
> +				exit(EXIT_SUCCESS);
> +			case '?':
> +				usage();
> +				exit(EXIT_FAILURE);
> +			default:
> +				exit(EXIT_FAILURE);
>  		}
>  	}
> -	return ret;
> +
> +	if (argc - optind > 0) {
> +		for (i = optind + 1; i < argc; i++) {
> +			printf ("Non-option argument %s\n", argv[i]);
> +		}
> +	} else {
> +		usage();
> +		exit(EXIT_FAILURE);
> +	}
> +
> +	(*arg) = optind;
> +
> +	return 0;
>  }
>  
>  static int init_trace_path(void)
> @@ -263,16 +279,19 @@ int main(int argc, char *argv[])
>  	int arg = 1;
>  	sigset_t saved_mask;
>  
> -	if (argc < 2)
> +	progname = argv[0];
> +
> +	if (argc < 2) {
> +		usage();
>  		return -ENOENT;
> +	}
>  
> -	euid = geteuid();
>  	uid = getuid();
>  	egid = getegid();
>  	gid = geteuid();
>  
>  	if (euid != 0 && uid != 0) {
> -		printf("%s must be setuid root\n", argv[0]);
> +		printf("%s must be setuid root\n", progname);
>  		return -EPERM;
>  	}
>  
> @@ -281,11 +300,9 @@ int main(int argc, char *argv[])
>  	printf_dbg("egid: %d\n", egid);
>  	printf_dbg("gid: %d\n", gid);
>  
> -	if (arg < argc) {
> -		ret = parse_options(argc, argv, &arg);
> -		if (ret)
> -			return ret;
> -	}
> +	ret = parse_options(argc, argv, &arg);
> +	if (ret)
> +		return ret;
>  
>  	ret = init_trace_path();
>  	gret = (gret == 0) ? ret : gret;
> -- 
> 1.7.3.2
> 
> 
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> ltt-dev at lists.casi.polymtl.ca
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> 

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com