Improve implementation of cat(1).
This commit is contained in:
Jonas 'Sortie' Termansen
parent
ad9a90926d
commit
a7b03af9cc
178
utils/cat.cpp
178
utils/cat.cpp
|
|
@ -1,6 +1,6 @@
|
|||
/*******************************************************************************
|
||||
|
||||
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012.
|
||||
Copyright(C) Jonas 'Sortie' Termansen 2013.
|
||||
|
||||
This program is free software: you can redistribute it and/or modify it
|
||||
under the terms of the GNU General Public License as published by the Free
|
||||
|
|
@ -16,94 +16,156 @@
|
|||
this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
|
||||
cat.cpp
|
||||
Concatenate files and print on the standard output.
|
||||
Concatenate and print files to the standard output.
|
||||
|
||||
*******************************************************************************/
|
||||
|
||||
#include <unistd.h>
|
||||
#include <string.h>
|
||||
#include <stdlib.h>
|
||||
#include <stdio.h>
|
||||
#include <fcntl.h>
|
||||
#include <sys/stat.h>
|
||||
|
||||
#include <errno.h>
|
||||
#include <error.h>
|
||||
#include <fcntl.h>
|
||||
#include <stdint.h>
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
#include <unistd.h>
|
||||
|
||||
int docat(const char* inputname, int fd)
|
||||
#if !defined(VERSIONSTR)
|
||||
#define VERSIONSTR "unknown version"
|
||||
#endif
|
||||
|
||||
static bool cat_fd(int fd, const char* path)
|
||||
{
|
||||
do
|
||||
struct stat st;
|
||||
if ( fstat(fd, &st) == 0 )
|
||||
{
|
||||
const size_t BUFFER_SIZE = 255;
|
||||
char buffer[BUFFER_SIZE+1];
|
||||
ssize_t bytesread = read(fd, buffer, BUFFER_SIZE);
|
||||
if ( bytesread == 0 ) { break; }
|
||||
if ( bytesread < 0 )
|
||||
if ( S_ISDIR(st.st_mode) )
|
||||
return error(0, EISDIR, "`%s'", path), false;
|
||||
}
|
||||
|
||||
const size_t BUFFER_SIZE = 16 * 1024;
|
||||
uint8_t buffer[BUFFER_SIZE];
|
||||
|
||||
ssize_t buffer_used;
|
||||
while ( 0 < (buffer_used = read(fd, buffer, BUFFER_SIZE)) )
|
||||
{
|
||||
size_t so_far = 0;
|
||||
while ( so_far < (size_t) buffer_used )
|
||||
{
|
||||
error(0, errno, "read: %s", inputname);
|
||||
return 1;
|
||||
ssize_t amount = write(1, buffer + so_far, buffer_used - so_far);
|
||||
if ( amount <= 0 )
|
||||
return error(0, errno, "`%s'", "<stdout>"), false;
|
||||
so_far += amount;
|
||||
}
|
||||
if ( (ssize_t) writeall(1, buffer, bytesread) < bytesread )
|
||||
}
|
||||
|
||||
if ( buffer_used < 0 )
|
||||
return error(0, errno, "`%s'", path), false;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
static bool cat_path(const char* path)
|
||||
{
|
||||
if ( !strcmp("-", path) )
|
||||
return cat_fd(0, "<stdin>");
|
||||
int fd = open(path, O_RDONLY);
|
||||
if ( fd < 0 )
|
||||
{
|
||||
error(0, errno, "`%s'", path);
|
||||
return false;
|
||||
}
|
||||
bool result = cat_fd(fd, path);
|
||||
close(fd);
|
||||
return result;
|
||||
}
|
||||
|
||||
static bool cat_arguments(int argc, char* argv[])
|
||||
{
|
||||
if ( argc <= 1 )
|
||||
return cat_path("-");
|
||||
bool success = true;
|
||||
for ( int i = 1; i < argc; i++ )
|
||||
if ( !cat_path(argv[i]) )
|
||||
success = false;
|
||||
return success;
|
||||
}
|
||||
|
||||
static void compact_arguments(int* argc, char*** argv)
|
||||
{
|
||||
for ( int i = 0; i < *argc; i++ )
|
||||
while ( i < *argc && !(*argv)[i] )
|
||||
{
|
||||
error(0, errno, "write: <stdout>", inputname);
|
||||
return 1;
|
||||
for ( int n = i; n < *argc; n++ )
|
||||
(*argv)[n] = (*argv)[n+1];
|
||||
(*argc)--;
|
||||
}
|
||||
} while ( true );
|
||||
return 0;
|
||||
}
|
||||
|
||||
void usage(FILE* fp, const char* argv0)
|
||||
static void usage(FILE* fp, const char* argv0)
|
||||
{
|
||||
fprintf(fp, "usage: %s [FILE ...]\n", argv0);
|
||||
fprintf(fp, "Concatenate files and print on the standard output.\n");
|
||||
fprintf(fp, "Usage: %s [OPTION]... [FILE]...\n", argv0);
|
||||
fprintf(fp, "Concatenate FILE(s), or standard input, to standard output.\n");
|
||||
fprintf(fp, "\n");
|
||||
fprintf(fp, " -u (ignored)\n");
|
||||
fprintf(fp, " --help display this help and exit\n");
|
||||
fprintf(fp, " --usage display this help and exit\n");
|
||||
fprintf(fp, " --version output version information and exit\n");
|
||||
fprintf(fp, "\n");
|
||||
fprintf(fp, "With no FILE, or when FILE is -, read standard input.\n");
|
||||
}
|
||||
|
||||
void help(FILE* fp, const char* argv0)
|
||||
static void help(FILE* fp, const char* argv0)
|
||||
{
|
||||
return usage(fp, argv0);
|
||||
usage(fp, argv0);
|
||||
}
|
||||
|
||||
void version(FILE* fp, const char* argv0)
|
||||
static void version(FILE* fp, const char* argv0)
|
||||
{
|
||||
return usage(fp, argv0);
|
||||
fprintf(fp, "%s (Sortix) %s\n", argv0, VERSIONSTR);
|
||||
fprintf(fp, "License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.\n");
|
||||
fprintf(fp, "This is free software: you are free to change and redistribute it.\n");
|
||||
fprintf(fp, "There is NO WARRANTY, to the extent permitted by law.\n");
|
||||
}
|
||||
|
||||
int main(int argc, char* argv[])
|
||||
{
|
||||
const char* argv0 = argv[0];
|
||||
|
||||
for ( int i = 1; i < argc; i++ )
|
||||
for ( int i = 0; i < argc; i++ )
|
||||
{
|
||||
const char* arg = argv[i];
|
||||
if ( arg[0] != '-' ) { continue; }
|
||||
argv[i] = NULL;
|
||||
if ( !strcmp(arg, "--") ) { break; }
|
||||
if ( !strcmp(arg, "--help") ) { help(stdout, argv0); exit(0); }
|
||||
if ( !strcmp(arg, "--usage") ) { usage(stdout, argv0); exit(0); }
|
||||
if ( !strcmp(arg, "--version") ) { version(stdout, argv0); exit(0); }
|
||||
error(0, 0, "unrecognized option: %s", arg);
|
||||
usage(stderr, argv0);
|
||||
exit(1);
|
||||
}
|
||||
|
||||
int result = 0;
|
||||
|
||||
bool any = false;
|
||||
for ( int i = 1; i < argc; i++ )
|
||||
{
|
||||
if ( !argv[i] ) { continue; }
|
||||
any = true;
|
||||
int fd = open(argv[i], O_RDONLY);
|
||||
if ( fd < 0 )
|
||||
{
|
||||
error(0, errno, "%s", argv[i]);
|
||||
result = 1;
|
||||
if ( arg[0] != '-' || !arg[1] )
|
||||
continue;
|
||||
argv[i] = NULL;
|
||||
if ( !strcmp(arg, "--") )
|
||||
break;
|
||||
if ( arg[1] != '-' )
|
||||
{
|
||||
while ( char c = *++arg ) switch ( c )
|
||||
{
|
||||
case 'u': /* Ignored, POSIX compatibility. */ break;
|
||||
default:
|
||||
fprintf(stderr, "%s: unknown option -- '%c'\n", argv0, c);
|
||||
usage(stderr, argv0);
|
||||
exit(1);
|
||||
}
|
||||
}
|
||||
else if ( !strcmp(arg, "--help") )
|
||||
help(stdout, argv0), exit(0);
|
||||
else if ( !strcmp(arg, "--usage") )
|
||||
usage(stdout, argv0), exit(0);
|
||||
else if ( !strcmp(arg, "--version") )
|
||||
version(stdout, argv0), exit(0);
|
||||
else
|
||||
{
|
||||
fprintf(stderr, "%s: unknown option: %s\n", argv0, arg);
|
||||
usage(stderr, argv0);
|
||||
exit(1);
|
||||
}
|
||||
|
||||
result |= docat(argv[i], fd);
|
||||
close(fd);
|
||||
}
|
||||
|
||||
if ( !any ) { result = docat("<stdin>", 0); }
|
||||
compact_arguments(&argc, &argv);
|
||||
|
||||
return result;
|
||||
return cat_arguments(argc, argv) ? 0 : 1;
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue