From: Christian Kastner <ckk@kvr.at>
Date: Tue, 18 Feb 2014 17:57:16 +0100
Subject: Improve option parsing

Detect errors when parsing numeric arguments, check for the right number of
arguments, and use optarg(3) if possible.

Bug-Debian: http://bugs.debian.org/716115
Forwarded: yes
Last-Update: 2019-10-21
---
 predict.c | 51 +++++++++++++++++++++++++++------------------------
 train.c   | 47 ++++++++++++++++++++++++++++++++++++++---------
 2 files changed, 65 insertions(+), 33 deletions(-)

diff --git a/predict.c b/predict.c
index 85ed067..968ceeb 100644
--- a/predict.c
+++ b/predict.c
@@ -3,6 +3,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
+#include <unistd.h>
 #include "linear.h"
 
 int print_null(const char *s,...) {return 0;}
@@ -186,48 +187,50 @@ void exit_with_help()
 int main(int argc, char **argv)
 {
 	FILE *input, *output;
-	int i;
+	int opt;
 
 	// parse options
-	for(i=1;i<argc;i++)
-	{
-		if(argv[i][0] != '-') break;
-		++i;
-		switch(argv[i-1][1])
-		{
-			case 'b':
-				flag_predict_probability = atoi(argv[i]);
-				break;
-			case 'q':
-				info = &print_null;
-				i--;
-				break;
-			default:
-				fprintf(stderr,"unknown option: -%c\n", argv[i-1][1]);
+	while ((opt = getopt(argc, argv, "b:q")) != -1) {
+		switch(opt) {
+		case 'b':
+			if (strcmp(optarg, "0") == 0) {
+				flag_predict_probability = 0;
+			} else if (strcmp(optarg, "1") == 0) {
+				flag_predict_probability = 1;
+			} else {
 				exit_with_help();
-				break;
+			}
+			break;
+		case 'q':
+			info = &print_null;
+			break;
+		default:
+			exit_with_help();
+			break;
 		}
 	}
-	if(i>=argc)
+
+	// Besides options, we expect exactly 3 arguments
+	if(optind+3 != argc)
 		exit_with_help();
 
-	input = fopen(argv[i],"r");
+	input = fopen(argv[optind],"r");
 	if(input == NULL)
 	{
-		fprintf(stderr,"can't open input file %s\n",argv[i]);
+		fprintf(stderr,"can't open input file %s\n",argv[optind]);
 		exit(1);
 	}
 
-	output = fopen(argv[i+2],"w");
+	output = fopen(argv[optind+2],"w");
 	if(output == NULL)
 	{
-		fprintf(stderr,"can't open output file %s\n",argv[i+2]);
+		fprintf(stderr,"can't open output file %s\n",argv[optind+2]);
 		exit(1);
 	}
 
-	if((model_=load_model(argv[i+1]))==0)
+	if((model_=load_model(argv[optind+1]))==0)
 	{
-		fprintf(stderr,"can't open model file %s\n",argv[i+1]);
+		fprintf(stderr,"can't open model file %s\n",argv[optind+1]);
 		exit(1);
 	}
 
diff --git a/train.c b/train.c
index 7923a8d..dc530cc 100644
--- a/train.c
+++ b/train.c
@@ -4,6 +4,7 @@
 #include <string.h>
 #include <ctype.h>
 #include <errno.h>
+#include <limits.h>
 #include "linear.h"
 #define Malloc(type,n) (type *)malloc((n)*sizeof(type))
 #define INF HUGE_VAL
@@ -66,6 +67,34 @@ void exit_input_error(int line_num)
 	exit(1);
 }
 
+static long strtol_or_exit(const char *str) {
+	errno = 0;
+	char *endptr;
+	long val = strtol(str, &endptr, 10);
+
+	if ((errno == ERANGE && (val == LONG_MAX || val == LONG_MIN)) || (errno != 0 && val == 0)) {
+		perror("error converting %s to int:");
+		exit_with_help();
+	} else if (*endptr != '\0') {
+		exit_with_help();
+	}
+	return val;
+}
+
+static float strtof_or_exit(const char *str) {
+	errno = 0;
+	char *endptr;
+	float val = strtof(str, &endptr);
+
+	if ((errno == ERANGE && (val == HUGE_VALF || val == HUGE_VALL)) || (errno != 0 && val == 0.0)) {
+		perror("error converting %s to float:");
+		exit_with_help();
+	} else if (*endptr != '\0') {
+		exit_with_help();
+	}
+	return val;
+}
+
 static char *line = NULL;
 static int max_line_len;
 
@@ -240,43 +269,43 @@ void parse_command_line(int argc, char **argv, char *input_file_name, char *mode
 		switch(argv[i-1][1])
 		{
 			case 's':
-				param.solver_type = atoi(argv[i]);
+				param.solver_type = strtol_or_exit(argv[i]);
 				flag_solver_specified = 1;
 				break;
 
 			case 'c':
-				param.C = atof(argv[i]);
+				param.C = strtof_or_exit(argv[i]);
 				flag_C_specified = 1;
 				break;
 
 			case 'p':
 				flag_p_specified = 1;
-				param.p = atof(argv[i]);
+				param.p = strtof_or_exit(argv[i]);
 				break;
 
 			case 'n':
-				param.nu = atof(argv[i]);
+				param.nu = strtof_or_exit(argv[i]);
 				break;
 
 			case 'e':
-				param.eps = atof(argv[i]);
+				param.eps = strtof_or_exit(argv[i]);
 				break;
 
 			case 'B':
-				bias = atof(argv[i]);
+				bias = strtof_or_exit(argv[i]);
 				break;
 
 			case 'w':
 				++param.nr_weight;
 				param.weight_label = (int *) realloc(param.weight_label,sizeof(int)*param.nr_weight);
 				param.weight = (double *) realloc(param.weight,sizeof(double)*param.nr_weight);
-				param.weight_label[param.nr_weight-1] = atoi(&argv[i-1][2]);
-				param.weight[param.nr_weight-1] = atof(argv[i]);
+				param.weight_label[param.nr_weight-1] = strtol_or_exit(&argv[i-1][2]);
+				param.weight[param.nr_weight-1] = strtof_or_exit(argv[i]);
 				break;
 
 			case 'v':
 				flag_cross_validation = 1;
-				nr_fold = atoi(argv[i]);
+				nr_fold = strtol_or_exit(argv[i]);
 				if(nr_fold < 2)
 				{
 					fprintf(stderr,"n-fold cross validation: n must >= 2\n");