options.c

#if HAVE_CONFIG_H
#include "config.h"
#endif

#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <limits.h>

#if HAVE_GETOPT_H
#include <getopt.h>
#endif

#include "ltrace.h"
#include "options.h"
#include "defs.h"

#define MAX_LIBRARY		30
char *library[MAX_LIBRARY];
int library_num = 0;
static char *progname;		/* Program name (`ltrace') */
FILE *output;
int opt_a = DEFAULT_ACOLUMN;	/* default alignment column for results */
int opt_c = 0;			/* Count time, calls, and report a summary on program exit */
int opt_d = 0;			/* debug */
int opt_i = 0;			/* instruction pointer */
int opt_s = DEFAULT_STRLEN;	/* default maximum # of bytes printed in strings */
int opt_S = 0;			/* display syscalls */
int opt_L = 1;			/* display library calls */
int opt_f = 0;			/* trace child processes as they are created */
char *opt_u = NULL;		/* username to run command as */
int opt_r = 0;			/* print relative timestamp */
int opt_t = 0;			/* print absolute timestamp */
#ifdef USE_DEMANGLE
int opt_C = 0;			/* Demangle low-level symbol names into user-level names */
#endif
int opt_n = 0;			/* indent trace output according to program flow */
int opt_T = 0;			/* show the time spent inside each call */

/* List of pids given to option -p: */
struct opt_p_t *opt_p = NULL;	/* attach to process with a given pid */

/* List of function names given to option -e: */
struct opt_e_t *opt_e = NULL;
int opt_e_enable = 1;

static void usage(void)
{
#if !(HAVE_GETOPT || HAVE_GETOPT_LONG)
	fprintf(stdout, "Usage: %s [command [arg ...]]\n"
		"Trace library calls of a given program.\n\n", progname);
#else
	fprintf(stdout, "Usage: %s [option ...] [command [arg ...]]\n"
		"Trace library calls of a given program.\n\n"
# if HAVE_GETOPT_LONG
		"  -a, --align=COLUMN  align return values in a secific column.\n"
# else
		"  -a COLUMN           align return values in a secific column.\n"
# endif
		"  -c                  count time and calls, and report a summary on exit.\n"
# ifdef USE_DEMANGLE
#  if HAVE_GETOPT_LONG
		"  -C, --demangle      decode low-level symbol names into user-level names.\n"
#  else
		"  -C                  decode low-level symbol names into user-level names.\n"
#  endif
# endif
# if HAVE_GETOPT_LONG
		"  -d, --debug         print debugging info.\n"
# else
		"  -d                  print debugging info.\n"
# endif
		"  -e expr             modify which events to trace.\n"
		"  -f                  follow forks.\n"
# if HAVE_GETOPT_LONG
		"  -h, --help          display this help and exit.\n"
# else
		"  -h                  display this help and exit.\n"
# endif
		"  -i                  print instruction pointer at time of library call.\n"
#  if HAVE_GETOPT_LONG
		"  -l, --library=FILE  print library calls from this library only.\n"
#  else
		"  -l FILE             print library calls from this library only.\n"
#  endif
		"  -L                  do NOT display library calls.\n"
# if HAVE_GETOPT_LONG
		"  -n, --indent=NR     indent output by NR spaces for each call level nesting.\n"
# else
		"  -n NR               indent output by NR spaces for each call level nesting.\n"
# endif
# if HAVE_GETOPT_LONG
		"  -o, --output=FILE   write the trace output to that file.\n"
# else
		"  -o FILE             write the trace output to that file.\n"
# endif
		"  -p PID              attach to the process with the process ID pid.\n"
		"  -r                  print relative timestamps.\n"
		"  -s STRLEN           specify the maximum string size to print.\n"
		"  -S                  display system calls.\n"
		"  -t, -tt, -ttt       print absolute timestamps.\n"
		"  -T                  show the time spent inside each call.\n"
		"  -u USERNAME         run command with the userid, groupid of username.\n"
# if HAVE_GETOPT_LONG
		"  -V, --version       output version information and exit.\n"
# else
		"  -V                  output version information and exit.\n"
# endif
		"\nReport bugs to Juan Cespedes <cespedes@debian.org>\n",
		progname);
#endif
}

static char *search_for_command(char *filename)
{
	static char pathname[PATH_MAX];
	char *path;
	int m, n;

	if (strchr(filename, '/')) {
		return filename;
	}
	for (path = getenv("PATH"); path && *path; path += m) {
		if (strchr(path, ':')) {
			n = strchr(path, ':') - path;
			m = n + 1;
		} else {
			m = n = strlen(path);
		}
		if (n + strlen(filename) + 1 >= PATH_MAX) {
			fprintf(stderr, "Error: filename too long\n");
			exit(1);
		}
		strncpy(pathname, path, n);
		if (n && pathname[n - 1] != '/') {
			pathname[n++] = '/';
		}
		strcpy(pathname + n, filename);
		if (!access(pathname, X_OK)) {
			return pathname;
		}
	}
	return filename;
}

char **process_options(int argc, char **argv)
{
	progname = argv[0];
	output = stderr;

#if HAVE_GETOPT || HAVE_GETOPT_LONG
	while (1) {
		int c;
#if HAVE_GETOPT_LONG
		int option_index = 0;
		static struct option long_options[] = {
			{"align", 1, 0, 'a'},
			{"debug", 0, 0, 'd'},
# ifdef USE_DEMANGLE
			{"demangle", 0, 0, 'C'},
#endif
			{"indent", 1, 0, 'n'},
			{"help", 0, 0, 'h'},
			{"library", 1, 0, 'l'},
			{"output", 1, 0, 'o'},
			{"version", 0, 0, 'V'},
			{0, 0, 0, 0}
		};
		c = getopt_long(argc, argv, "+cdfhiLrStTV"
# ifdef USE_DEMANGLE
				"C"
# endif
				"a:e:l:n:o:p:s:u:", long_options,
				&option_index);
#else
		c = getopt(argc, argv, "+cdfhiLrStTV"
# ifdef USE_DEMANGLE
			   "C"
# endif
			   "a:e:l:n:o:p:s:u:");
#endif
		if (c == -1) {
			break;
		}
		switch (c) {
		case 'a':
			opt_a = atoi(optarg);
			break;
		case 'c':
			opt_c++;
			break;
#ifdef USE_DEMANGLE
		case 'C':
			opt_C++;
			break;
#endif
		case 'd':
			opt_d++;
			break;
		case 'e':
			{
				char *str_e = strdup(optarg);
				if (!str_e) {
					perror("ltrace: strdup");
					exit(1);
				}
				if (str_e[0] == '!') {
					opt_e_enable = 0;
					str_e++;
				}
				while (*str_e) {
					struct opt_e_t *tmp;
					char *str2 = strchr(str_e, ',');
					if (str2) {
						*str2 = '\0';
					}
					tmp = malloc(sizeof(struct opt_e_t));
					if (!tmp) {
						perror("ltrace: malloc");
						exit(1);
					}
					tmp->name = str_e;
					tmp->next = opt_e;
					opt_e = tmp;
					if (str2) {
						str_e = str2 + 1;
					} else {
						break;
					}
				}
				break;
			}
		case 'f':
			opt_f = 1;
			break;
		case 'h':
			usage();
			exit(0);
		case 'i':
			opt_i++;
			break;
		case 'l':
			if (library_num == MAX_LIBRARY) {
				fprintf(stderr,
					"Too many libraries.  Maximum is %i.\n",
					MAX_LIBRARY);
				exit(1);
			}
			library[library_num++] = optarg;
			break;
		case 'L':
			opt_L = 0;
			break;
		case 'n':
			opt_n = atoi(optarg);
			break;
		case 'o':
			output = fopen(optarg, "w");
			if (!output) {
				fprintf(stderr,
					"Can't open %s for output: %s\n",
					optarg, strerror(errno));
				exit(1);
			}
			setvbuf(output, (char *)NULL, _IOLBF, 0);
			fcntl(fileno(output), F_SETFD, FD_CLOEXEC);
			break;
		case 'p':
			{
				struct opt_p_t *tmp =
				    malloc(sizeof(struct opt_p_t));
				if (!tmp) {
					perror("ltrace: malloc");
					exit(1);
				}
				tmp->pid = atoi(optarg);
				tmp->next = opt_p;
				opt_p = tmp;
				break;
			}
		case 'r':
			opt_r++;
			break;
		case 's':
			opt_s = atoi(optarg);
			break;
		case 'S':
			opt_S = 1;
			break;
		case 't':
			opt_t++;
			break;
		case 'T':
			opt_T++;
			break;
		case 'u':
			opt_u = optarg;
			break;
		case 'V':
			printf("ltrace version " PACKAGE_VERSION ".\n"
			       "Copyright (C) 1997-2006 Juan Cespedes <cespedes@debian.org>.\n"
			       "This is free software; see the GNU General Public Licence\n"
			       "version 2 or later for copying conditions.  There is NO warranty.\n");
			exit(0);

		default:
#if HAVE_GETOPT_LONG
			fprintf(stderr,
				"Try `%s --help' for more information\n",
				progname);
#else
			fprintf(stderr, "Try `%s -h' for more information\n",
				progname);
#endif
			exit(1);
		}
	}
	argc -= optind;
	argv += optind;
#endif

	if (!opt_p && argc < 1) {
		fprintf(stderr, "%s: too few arguments\n", progname);
		usage();
		exit(1);
	}
	if (opt_r && opt_t) {
		fprintf(stderr, "%s: Incompatible options -r and -t\n",
			progname);
		exit(1);
	}
	if (argc > 0) {
		command = search_for_command(argv[0]);
	}
	return &argv[0];
}