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/*
* Copyright (c) 2012 Tim Ruehsen
* Copyright (c) 2015-2024 Free Software Foundation, Inc.
*
* This file is part of libwget.
*
* Libwget is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Libwget is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with libwget. If not, see <https://www.gnu.org/licenses/>.
*
*
* a collection of pipe/popen routines
*
* Changelog
* 25.04.2012 Tim Ruehsen created
*
*/
#include <config.h>
#ifndef _WIN32
#include <stddef.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <wget.h>
#include "private.h"
FILE *wget_vpopenf(const char *type, const char *fmt, va_list args)
{
FILE *fp = NULL;
char sbuf[1024];
wget_buffer buf;
if (!type || !fmt)
return NULL;
wget_buffer_init(&buf, sbuf, sizeof(sbuf));
wget_buffer_vprintf(&buf, fmt, args);
fp = popen(buf.data, type);
wget_buffer_deinit(&buf);
return fp;
}
FILE *wget_popenf(const char *type, const char *fmt, ...)
{
FILE *fp;
va_list args;
va_start(args, fmt);
fp = wget_vpopenf(type, fmt, args);
va_end(args);
return fp;
}
pid_t wget_fd_popen3(int *fdin, int *fdout, int *fderr, const char *const *argv)
{
int pipefd_in[2]; // child's STDIN
int pipefd_out[2]; // child's STDOUT
int pipefd_err[2]; // child's STDERR
pid_t pid;
if (!argv)
return -1;
// create a pipe. the child writes into it and the parent read from it.
// pipefd[0]=reader pipefd[1]=writer
if (fdin && pipe(pipefd_in) == -1) {
error_printf(_("Failed to create pipe for STDIN on %s\n"), argv[0]);
return -1;
}
if (fdout && pipe(pipefd_out) == -1) {
error_printf(_("Failed to create pipe for STDOUT on %s\n"), argv[0]);
if (fdin) {
close(pipefd_in[0]);
close(pipefd_in[1]);
}
return -1;
}
if (fderr && fderr != fdout && pipe(pipefd_err) == -1) {
error_printf(_("Failed to create pipe for STDERR on %s\n"), argv[0]);
if (fdin) {
close(pipefd_in[0]);
close(pipefd_in[1]);
}
if (fdout) {
close(pipefd_out[0]);
close(pipefd_out[1]);
}
return -1;
}
if ((pid = fork()) == 0) {
if (fdin) {
close(pipefd_in[1]); // the STDIN writer is not needed by the child
// redirect STDIN to reader
if (dup2(pipefd_in[0], STDIN_FILENO) == -1)
error_printf_exit(_("Failed to dup2(%d,%d) (%d)\n"), pipefd_in[0], STDIN_FILENO, errno);
close(pipefd_in[0]); // the old STDIN reader is not needed any more
}
if (fdout) {
close(pipefd_out[0]); // the STDOUT reader is not needed by the child
// redirect STDOUT to writer
if (dup2(pipefd_out[1], STDOUT_FILENO) == -1)
error_printf_exit(_("Failed to dup2(%d,%d) (%d)\n"), pipefd_out[1], STDOUT_FILENO, errno);
close(pipefd_out[1]); // the old STDOUT writer is not needed any more
}
if (fderr) {
if (fderr != fdout) {
close(pipefd_err[0]); // the STDERR reader is not needed by the child
// redirect STDERR to writer
if (dup2(pipefd_err[1], STDERR_FILENO) == -1)
error_printf_exit(_("Failed to dup2(%d,%d) (%d)\n"), pipefd_err[1], STDERR_FILENO, errno);
close(pipefd_err[1]); // the old STDERR writer is not needed any more
} else {
// redirect STDERR to STDOUT
if (dup2(STDOUT_FILENO, STDERR_FILENO) == -1)
exit(EXIT_FAILURE);
}
}
execvp(argv[0], (char *const *)argv); // does only return on error
// error_printf(_("Failed to execute %s (%d)\n"),argv[0],errno);
exit(EXIT_FAILURE);
} else if (pid < 0) {
// fork error
if (fdin) {
close(pipefd_in[0]);
close(pipefd_in[1]);
}
if (fdout) {
close(pipefd_out[0]);
close(pipefd_out[1]);
}
if (fderr && fderr != fdout) {
close(pipefd_err[0]);
close(pipefd_err[1]);
}
error_printf(_("Failed to fork '%s'\n"), argv[0]);
return pid;
}
// parent
if (fdin) {
close(pipefd_in[0]); // the STDIN reader is not needed by the parent
*fdin = pipefd_in[1];
}
if (fdout) {
close(pipefd_out[1]); // the STDOUT writer is not needed by the parent
*fdout = pipefd_out[0];
}
if (fderr && fderr != fdout) {
close(pipefd_err[1]); // the STDERR writer is not needed by the parent
*fderr = pipefd_err[0];
}
return pid;
}
// extended popen to have control over the child's STDIN, STDOUT and STDERR
// NULL to ignore child's STDxxx
// if fpout==fperr STDERR will be redirected to STDOUT
// fpin: child's stdin (that's where the calling process can write data into)
// fpout: child's stdout (that's where the calling process reads data from)
// fperr: child's stderr (that's where the calling process reads error messages from)
// argv: argument to execvp(), e.g. const char *argv[]={"ls","-la",NULL};
pid_t wget_popen3(FILE **fpin, FILE **fpout, FILE **fperr, const char *const *argv)
{
int fdin = -1, fdout = -1, fderr = -1;
pid_t pid;
if (fpin) *fpin = NULL;
if (fpout) *fpout = NULL;
if (fperr) *fperr = NULL;
if ((pid = wget_fd_popen3(fpin ? &fdin : NULL, fpout ? &fdout : NULL, fperr ? (fperr != fpout ? &fderr : &fdout) : NULL, argv)) > 0) {
if (fpin) *fpin = fdopen(fdin, "w");
if (fpout) *fpout = fdopen(fdout, "r");
if (fperr && fperr != fpout) *fperr = fdopen(fderr, "r");
}
return pid;
}
#endif
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