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AK/Userland: Add single value to ArgsParser usage, and port tail to use ArgsParser

This commit is contained in:
Robin Burchell 2019-05-17 12:59:37 +02:00 committed by Andreas Kling
parent c478503581
commit 6dd7ee53ea
3 changed files with 61 additions and 30 deletions

View file

@ -112,6 +112,12 @@ bool ArgsParser::check_required_args(const ArgsParserResult& res)
return false;
}
}
if (m_single_value_required) {
if (res.m_single_values.size() == 0)
return false;
}
return true;
}
@ -135,6 +141,18 @@ void ArgsParser::add_arg(const String& name, const String& value_name, const Str
m_args.set(name, Arg(name, value_name, description, false));
}
void ArgsParser::set_single_value(const String& name)
{
m_single_value_name = name;
m_single_value_required = false;
}
void ArgsParser::set_required_single_value(const String& name)
{
m_single_value_name = name;
m_single_value_required = true;
}
String ArgsParser::get_usage() const
{
StringBuilder sb;
@ -163,6 +181,20 @@ String ArgsParser::get_usage() const
sb.append("] ");
}
if (m_single_value_name.length()) {
if (m_single_value_required)
sb.append("<");
else
sb.append("[");
sb.append(m_single_value_name);
if (m_single_value_required)
sb.append(">");
else
sb.append("]");
}
sb.append("\n");
for (auto& it : m_args) {

View file

@ -38,6 +38,8 @@ public:
void add_required_arg(const String& name, const String& value_name, const String& description);
void add_arg(const String& name, const String& description);
void add_arg(const String& name, const String& value_name, const String& description);
void set_single_value(const String& name);
void set_required_single_value(const String& name);
String get_usage() const;
void print_usage() const;
@ -59,6 +61,8 @@ private:
String m_program_name;
String m_prefix;
String m_single_value_name;
bool m_single_value_required = false;
HashMap<String, Arg> m_args;
};

View file

@ -2,17 +2,11 @@
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <getopt.h>
#include <unistd.h>
#include <AK/Assertions.h>
#include <AK/ArgsParser.h>
#include <LibCore/CFile.h>
static void print_usage_and_exit()
{
printf("usage: tail [-f, -n <linecount>] <filename>\n");
exit(1);
}
int tail_from_pos(CFile& file, off_t startline, bool want_follow)
{
if (!file.seek(startline + 1))
@ -81,37 +75,38 @@ static void exit_because_we_wanted_lines()
int main(int argc, char *argv[])
{
AK::ArgsParser args_parser("tail");
args_parser.add_arg("f", "follow -- appended data is output as it is written to the file");
args_parser.add_arg("n", "lines", "fetch the specified number of lines");
args_parser.set_required_single_value("file");
AK::ArgsParserResult args = args_parser.parse(argc, (const char**)argv);
Vector<String> values = args.get_single_values();
if (values.size() != 1) {
args_parser.print_usage();
return -1;
}
int line_count = 0;
bool flag_follow = false;
int opt;
while ((opt = getopt(argc, argv, "fn:")) != -1) {
switch (opt) {
case 'f':
flag_follow = true;
break;
case 'n':
line_count = strtol(optarg, NULL, 10);
if (errno == EINVAL) {
exit_because_we_wanted_lines();
}
break;
default:
print_usage_and_exit();
if (args.is_present("n")) {
line_count = strtol(args.get("n").characters(), NULL, 10);
if (errno == EINVAL) {
args_parser.print_usage();
return -1;
}
}
const char *path = nullptr;
if (optind >= argc) {
print_usage_and_exit();
}
path = argv[optind];
CFile f(path);
CFile f(values[0]);
if (!f.open(CIODevice::ReadOnly)) {
fprintf(stderr, "Error opening file %s: %s\n", path, strerror(errno));
fprintf(stderr, "Error opening file %s: %s\n", f.filename().characters(), strerror(errno));
exit(-1);
}
bool flag_follow = args.is_present("f");
bool o_arg = args.is_present("o");
auto pos = find_seek_pos(f, line_count);
return tail_from_pos(f, pos, flag_follow);
}