1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
#include "util/io.h"
using namespace std;
namespace ov4
{
void safe_print(char *s, bool ignore_wrap)
{
int errno_old = errno;
if (ignore_wrap)
for (int i = 0; s[i] != 0; i++)
if (s[i] == '\n')
{
write(STDOUT_FILENO, s, i);
return;
}
write(STDOUT_FILENO, s, strlen(s));
errno = errno_old;
}
void safe_print(int x)
{
int errno_old = errno;
char msg[LENGTH];
itoa(x, msg, DECIMAL);
safe_print(msg);
errno = errno_old;
}
void reverse(char str[], int length)
{
int errno_old = errno;
int start = 0;
int end = length - 1;
while (start < end) {
char temp = str[start];
str[start] = str[end];
str[end] = temp;
end--;
start++;
}
errno = errno_old;
}
void safe_debug(char *s, bool ignore_wrap)
{
int errno_old = errno;
if (verbose && GLOBAL_DEBUG) safe_print(s, ignore_wrap);
errno = errno_old;
}
void safe_debug(int x)
{
int errno_old = errno;
if (verbose && GLOBAL_DEBUG) safe_print(x);
errno = errno_old;
}
bool isnum(char *s)
{
int errno_old = errno;
for (int i = 0; s[i] != 0; i++)
if (!isdigit(s[i]))
return false;
return true;
errno = errno_old;
}
char *itoa(int num, char* str, int base)
{
int errno_old = errno;
int i = 0;
bool isNegative = false;
/* Handle 0 explicitly, otherwise empty string is
* printed for 0 */
if (num == 0) {
str[i++] = '0';
str[i] = '\0';
return str;
}
// In standard itoa(), negative numbers are handled
// only with base 10. Otherwise numbers are
// considered unsigned.
if (num < 0 && base == 10) {
isNegative = true;
num = -num;
}
// Process individual digits
while (num != 0) {
int rem = num % base;
str[i++] = (rem > 9) ? (rem - 10) + 'a' : rem + '0';
num = num / base;
}
// If number is negative, append '-'
if (isNegative)
str[i++] = '-';
str[i] = '\0'; // Append string terminator
// Reverse the string
reverse(str, i);
errno = errno_old;
return str;
}
/*
* usage - print a help message
*/
void usage(void)
{
printf("Usage: shell [-hvp]\n");
printf(" -h print this message\n");
printf(" -v print additional diagnostic information\n");
printf(" -p do not emit a command prompt\n");
exit(1);
}
/*
* unix_error - unix-style error routine
*/
void unix_error(char *msg)
{
fprintf(stdout, "%s: %s\n", msg, strerror(errno));
exit(1);
}
/*
* app_error - application-style error routine
*/
void app_error(char *msg)
{
fprintf(stdout, "%s\n", msg);
exit(1);
}
}
|
