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#pragma once
#include "defines.hpp"
#include <cstring>
template <uint16_t N>
class MaxLengthCString {
public:
MaxLengthCString() : m_strPos(0), m_boundsExceeded(false) {
m_str[0] = '\0';
}
inline void operator+=(char const* rhs) {
write(rhs, strlen(rhs));
}
void write(char const* data, size_t len) {
if (m_boundsExceeded || m_strPos + len >= N) {
m_boundsExceeded = true;
return;
}
memcpy(m_str + m_strPos, data, len);
m_strPos += len;
m_str[m_strPos] = '\0';
}
void write(char c) {
if (m_boundsExceeded || m_strPos + 1 >= N) {
m_boundsExceeded = true;
return;
}
m_str[m_strPos] = c;
m_strPos++;
}
void write_num(size_t num) {
size_t d = 1;
while (num / 10 >= d)
d *= 10;
while (num > 0) {
char c = '0' + (num / d);
write(c);
num %= d;
d /= 10;
}
}
char const* get_str() {
return m_str;
};
bool boundsExceeded() {
return m_boundsExceeded;
};
private:
char m_str[N];
size_t m_strPos;
bool m_boundsExceeded;
};
template <uint16_t BUFSIZE>
class BufFileWriter {
public:
inline BufFileWriter(int fd_) : m_writeBufPos(0), m_fd(fd_) {}
~BufFileWriter() {
flush();
}
void write(char const* data, size_t len) {
while (len > 0) {
size_t to_add = std::min(len, (size_t)BUFSIZE - m_writeBufPos);
memcpy(m_writeBuf + m_writeBufPos, data, to_add);
data += to_add;
len -= to_add;
m_writeBufPos += to_add;
if (m_writeBufPos == BUFSIZE)
flush();
}
}
inline void write(char c) {
if (m_writeBufPos == BUFSIZE)
flush();
m_writeBuf[m_writeBufPos] = c;
m_writeBufPos++;
}
inline void operator+=(char const* str) {
write(str, strlen(str));
}
inline void operator+=(std::string_view str) {
write(str.data(), str.size());
}
inline void operator+=(char c) {
write(c);
}
void writeNum(size_t num) {
size_t d = 1;
while (num / 10 >= d)
d *= 10;
while (num > 0) {
char c = '0' + (num / d);
write(c);
num %= d;
d /= 10;
}
}
void writeCmdOutput(const char* cmd) {
int pipefd[2];
if (pipe(pipefd) < 0) {
*this += "<pipe(pipefd) failed with";
writeNum(errno);
*this += ">\n";
return;
}
// terminate child instead of waiting
{
struct sigaction act;
act.sa_handler = SIG_DFL;
sigemptyset(&act.sa_mask);
act.sa_flags = SA_NOCLDWAIT;
#ifdef SA_RESTORER
act.sa_restorer = NULL;
#endif
sigaction(SIGCHLD, &act, NULL);
}
pid_t pid = fork();
if (pid < 0) {
*this += "<fork() failed with ";
writeNum(errno);
*this += ">\n";
return;
}
if (pid == 0) {
close(pipefd[0]);
dup2(pipefd[1], STDOUT_FILENO);
char const* const argv[] = {"/bin/sh", "-c", cmd, NULL};
execv("/bin/sh", (char* const*)argv);
BufFileWriter<64> failmsg(pipefd[1]);
failmsg += "<execv(";
failmsg += cmd;
failmsg += ") resulted in errno ";
failmsg.write(errno);
failmsg += ">\n";
close(pipefd[1]);
abort();
} else {
close(pipefd[1]);
long len;
char readbuf[256];
while ((len = read(pipefd[0], readbuf, 256)) > 0) {
write(readbuf, len);
}
if (len < 0) {
*this += "<interrupted, read() resulted in errno ";
writeNum(errno);
*this += ">\n";
}
close(pipefd[0]);
}
}
void flush() {
size_t i = 0;
while (i < m_writeBufPos) {
auto written = ::write(m_fd, m_writeBuf + i, m_writeBufPos - i);
if (written <= 0) {
return;
}
i += written;
}
m_writeBufPos = 0;
}
private:
char m_writeBuf[BUFSIZE];
size_t m_writeBufPos;
int m_fd;
};
char const* sig_getenv(char const* name);
char const* sig_strsignal(int sig);
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