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CUT.C
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1993-09-18
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602 lines
/* cut - remove parts of lines of files
Copyright (C) 1984 by David M. Ihnat
This program is a total rewrite of the Bell Laboratories Unix(Tm)
command of the same name, as of System V. It contains no proprietary
code, and therefore may be used without violation of any proprietary
agreements whatsoever. However, you will notice that the program is
copyrighted by me. This is to assure the program does *not* fall
into the public domain. Thus, I may specify just what I am now:
This program may be freely copied and distributed, provided this notice
remains; it may not be sold for profit without express written consent of
the author.
Please note that I recreated the behavior of the Unix(Tm) 'cut' command
as faithfully as possible; however, I haven't run a full set of regression
tests. Thus, the user of this program accepts full responsibility for any
effects or loss; in particular, the author is not responsible for any losses,
explicit or incidental, that may be incurred through use of this program.
I ask that any bugs (and, if possible, fixes) be reported to me when
possible. -David Ihnat (312) 784-4544 ignatz@homebru.chi.il.us
POSIX changes, bug fixes, long-named options, and cleanup
by David MacKenzie <djm@gnu.ai.mit.edu>.
Options:
--bytes=byte-list
-b byte-list Print only the bytes in positions listed
in BYTE-LIST.
Tabs and backspaces are treated like any
other character; they take up 1 byte.
--characters=character-list
-c character-list Print only characters in positions listed
in CHARACTER-LIST.
The same as -b for now, but
internationalization will change that.
Tabs and backspaces are treated like any
other character; they take up 1 character.
--fields=field-list
-f field-list Print only the fields listed in FIELD-LIST.
Fields are separated by a TAB by default.
--delimiter=delim
-d delim For -f, fields are separated by the first
character in DELIM instead of TAB.
-n Do not split multibyte chars (no-op for now).
--only-delimited
-s For -f, do not print lines that do not contain
the field separator character.
The BYTE-LIST, CHARACTER-LIST, and FIELD-LIST are one or more numbers
or ranges separated by commas. The first byte, character, and field
are numbered 1.
A FILE of `-' means standard input. */
/* Get isblank from GNU libc. */
#define _GNU_SOURCE
#include <stdio.h>
#include "../lib/getopt.h"
#include <sys/types.h>
#include "system.h"
#include "version.h"
char *xmalloc ();
char *xrealloc ();
void error ();
static int set_fields ();
static int cut_file ();
static void cut_stream ();
static void cut_bytes ();
static void cut_fields ();
static void enlarge_line ();
static void invalid_list ();
static void usage ();
/* The number of elements allocated for the input line
and the byte or field number.
Enlarged as necessary. */
static int line_size;
/* Processed output buffer. */
static char *outbuf;
/* Where to save next char to output. */
static char *outbufptr;
/* Raw line buffer for field mode. */
static char *inbuf;
/* Where to save next input char. */
static char *inbufptr;
/* What can be done about a byte or field. */
enum field_action
{
field_omit,
field_output
};
/* In byte mode, which bytes to output.
In field mode, which `delim'-separated fields to output.
Both bytes and fields are numbered starting with 1,
so the first element of `fields' is unused. */
static enum field_action *fields;
enum operating_mode
{
undefined_mode,
/* Output characters that are in the given bytes. */
byte_mode,
/* Output the given delimeter-separated fields. */
field_mode
};
/* The name this program was run with. */
char *program_name;
static enum operating_mode operating_mode;
/* If nonzero,
for field mode, do not output lines containing no delimeter characters. */
static int delimited_lines_only;
/* The delimeter character for field mode. */
static unsigned char delim;
/* Nonzero if we have ever read standard input. */
static int have_read_stdin;
/* If non-zero, display usage information and exit. */
static int flag_help;
/* If non-zero, print the version on standard error. */
static int flag_version;
static struct option const longopts[] =
{
{"bytes", required_argument, 0, 'b'},
{"characters", required_argument, 0, 'c'},
{"fields", required_argument, 0, 'f'},
{"delimiter", required_argument, 0, 'd'},
{"only-delimited", no_argument, 0, 's'},
{"help", no_argument, &flag_help, 1},
{"version", no_argument, &flag_version, 1},
{0, 0, 0, 0}
};
void
main (argc, argv)
int argc;
char **argv;
{
int optc, exit_status = 0;
program_name = argv[0];
line_size = 512;
operating_mode = undefined_mode;
delimited_lines_only = 0;
delim = '\0';
have_read_stdin = 0;
fields = (enum field_action *)
xmalloc (line_size * sizeof (enum field_action));
outbuf = (char *) xmalloc (line_size);
inbuf = (char *) xmalloc (line_size);
for (optc = 0; optc < line_size; optc++)
fields[optc] = field_omit;
while ((optc = getopt_long (argc, argv, "b:c:d:f:ns", longopts, (int *) 0))
!= EOF)
{
switch (optc)
{
case 0:
break;
case 'b':
case 'c':
/* Build the byte list. */
if (operating_mode != undefined_mode)
usage ();
operating_mode = byte_mode;
if (set_fields (optarg) == 0)
error (2, 0, "no fields given");
break;
case 'f':
/* Build the field list. */
if (operating_mode != undefined_mode)
usage ();
operating_mode = field_mode;
if (set_fields (optarg) == 0)
error (2, 0, "no fields given");
break;
case 'd':
/* New delimiter. */
if (optarg[0] == '\0')
error (2, 0, "no delimiter given");
if (optarg[1] != '\0')
error (2, 0, "delimiter must be a single character");
delim = optarg[0];
break;
case 'n':
break;
case 's':
delimited_lines_only++;
break;
default:
usage ();
}
}
if (flag_version)
{
fprintf (stderr, "%s\n", version_string);
exit (0);
}
if (flag_help)
usage ();
if (operating_mode == undefined_mode)
usage ();
if ((delimited_lines_only || delim != '\0') && operating_mode != field_mode)
usage ();
if (delim == '\0')
delim = '\t';
if (optind == argc)
exit_status |= cut_file ("-");
else
for (; optind < argc; optind++)
exit_status |= cut_file (argv[optind]);
if (have_read_stdin && fclose (stdin) == EOF)
{
error (0, errno, "-");
exit_status = 1;
}
if (ferror (stdout) || fclose (stdout) == EOF)
error (1, errno, "write error");
exit (exit_status);
}
/* Select for printing the positions in `fields' that are listed in
byte or field specification FIELDSTR. FIELDSTR should be
composed of one or more numbers or ranges of numbers, separated by
blanks or commas. Incomplete ranges may be given: `-m' means
`1-m'; `n-' means `n' through end of line or last field.
Return the number of fields selected. */
static int
set_fields (fieldstr)
char *fieldstr;
{
int initial = 1; /* Value of first number in a range. */
int dash_found = 0; /* Nonzero if a '-' is found in this field. */
int value = 0; /* If nonzero, a number being accumulated. */
int fields_selected = 0; /* Number of fields selected so far. */
/* If nonzero, index of first field in a range that goes to end of line. */
int eol_range_start = 0;
for (;;)
{
if (*fieldstr == '-')
{
/* Starting a range. */
if (dash_found)
invalid_list ();
dash_found++;
fieldstr++;
if (value)
{
if (value >= line_size)
enlarge_line (value);
initial = value;
value = 0;
}
else
initial = 1;
}
else if (*fieldstr == ',' || ISBLANK (*fieldstr) || *fieldstr == '\0')
{
/* Ending the string, or this field/byte sublist. */
if (dash_found)
{
dash_found = 0;
/* A range. Possibilites: -n, m-n, n-.
In any case, `initial' contains the start of the range. */
if (value == 0)
{
/* `n-'. From `initial' to end of line. */
eol_range_start = initial;
fields_selected++;
}
else
{
/* `m-n' or `-n' (1-n). */
if (value < initial)
invalid_list ();
if (value >= line_size)
enlarge_line (value);
/* Is there already a range going to end of line? */
if (eol_range_start != 0)
{
/* Yes. Is the new sequence already contained
in the old one? If so, no processing is
necessary. */
if (initial < eol_range_start)
{
/* No, the new sequence starts before the
old. Does the old range going to end of line
extend into the new range? */
if (eol_range_start < value)
/* Yes. Simply move the end of line marker. */
eol_range_start = initial;
else
{
/* No. A simple range, before and disjoint from
the range going to end of line. Fill it. */
for (; initial <= value; initial++)
fields[initial] = field_output;
}
/* In any case, some fields were selected. */
fields_selected++;
}
}
else
{
/* There is no range going to end of line. */
for (; initial <= value; initial++)
fields[initial] = field_output;
fields_selected++;
}
value = 0;
}
}
else if (value != 0)
{
/* A simple field number, not a range. */
if (value >= line_size)
enlarge_line (value);
fields[value] = field_output;
value = 0;
fields_selected++;
}
if (*fieldstr == '\0')
{
/* If there was a range going to end of line, fill the
array from the end of line point. */
if (eol_range_start)
for (initial = eol_range_start; initial < line_size; initial++)
fields[initial] = field_output;
return fields_selected;
}
fieldstr++;
}
else if (ISDIGIT (*fieldstr))
{
value = 10 * value + *fieldstr - '0';
fieldstr++;
}
else
invalid_list ();
}
}
/* Process file FILE to standard output.
Return 0 if successful, 1 if not. */
static int
cut_file (file)
char *file;
{
FILE *stream;
if (!strcmp (file, "-"))
{
have_read_stdin = 1;
stream = stdin;
}
else
{
stream = fopen (file, "r");
if (stream == NULL)
{
error (0, errno, "%s", file);
return 1;
}
}
cut_stream (stream);
if (ferror (stream))
{
error (0, errno, "%s", file);
return 1;
}
if (!strcmp (file, "-"))
clearerr (stream); /* Also clear EOF. */
else if (fclose (stream) == EOF)
{
error (0, errno, "%s", file);
return 1;
}
return 0;
}
static void
cut_stream (stream)
FILE *stream;
{
if (operating_mode == byte_mode)
cut_bytes (stream);
else
cut_fields (stream);
}
/* Print the file open for reading on stream STREAM
with the bytes marked `field_omit' in `fields' removed from each line. */
static void
cut_bytes (stream)
FILE *stream;
{
register int c; /* Each character from the file. */
int doneflag = 0; /* Nonzero if EOF reached. */
int char_count; /* Number of chars in the line so far. */
while (doneflag == 0)
{
/* Start processing a line. */
outbufptr = outbuf;
char_count = 0;
do
{
c = getc (stream);
if (c == EOF)
{
doneflag++;
break;
}
/* If this character is to be sent, stow it in the outbuffer. */
if (++char_count == line_size - 1)
enlarge_line (char_count);
if (fields[char_count] == field_output || c == '\n')
*outbufptr++ = c;
}
while (c != '\n');
if (char_count)
fwrite (outbuf, sizeof (char), outbufptr - outbuf, stdout);
}
}
/* Print the file open for reading on stream STREAM
with the fields marked `field_omit' in `fields' removed from each line.
All characters are initially stowed in the raw input buffer, until
at least one field has been found. */
static void
cut_fields (stream)
FILE *stream;
{
register int c; /* Each character from the file. */
int doneflag = 0; /* Nonzero if EOF reached. */
int char_count; /* Number of chars in line before any delim. */
int fieldfound; /* Nonzero if any fields to print found. */
int curr_field; /* Current index in `fields'. */
while (doneflag == 0)
{
char_count = 0;
fieldfound = 0;
curr_field = 1;
outbufptr = outbuf;
inbufptr = inbuf;
do
{
c = getc (stream);
if (c == EOF)
{
doneflag++;
break;
}
if (fields[curr_field] == field_output && c != '\n')
{
/* Working on a field. It, and its terminating
delimiter, go only into the processed buffer. */
fieldfound = 1;
if (outbufptr - outbuf == line_size - 2)
enlarge_line (outbufptr - outbuf);
*outbufptr++ = c;
}
else if (fieldfound == 0)
{
if (++char_count == line_size - 1)
enlarge_line (char_count);
*inbufptr++ = c;
}
if (c == delim && ++curr_field == line_size - 1)
enlarge_line (curr_field);
}
while (c != '\n');
if (fieldfound)
{
/* Something was found. Print it. */
if ((unsigned char) outbufptr[-1] == delim)
--outbufptr; /* Suppress trailing delimiter. */
fwrite (outbuf, sizeof (char), outbufptr - outbuf, stdout);
if (c == '\n')
putc (c, stdout);
}
else if (!delimited_lines_only && char_count)
/* A line with some characters, no delimiters, and no
suppression. Print it. */
fwrite (inbuf, sizeof (char), inbufptr - inbuf, stdout);
}
}
/* Extend the buffers to accomodate at least NEW_SIZE characters. */
static void
enlarge_line (new_size)
int new_size;
{
char *newp;
int i;
new_size += 256; /* Leave some room to grow. */
fields = (enum field_action *)
xrealloc (fields, new_size * sizeof (enum field_action));
newp = (char *) xrealloc (outbuf, new_size);
outbufptr += newp - outbuf;
outbuf = newp;
newp = (char *) xrealloc (inbuf, new_size);
inbufptr += newp - inbuf;
inbuf = newp;
for (i = line_size; i < new_size; i++)
fields[i] = field_omit;
line_size = new_size;
}
static void
invalid_list ()
{
error (2, 0, "invalid byte or field list");
}
static void
usage ()
{
fprintf (stderr, "\
Usage: %s {-b byte-list,--bytes=byte-list} [-n] [file...] <options> \n\
%s {-c character-list,--characters=character-list} <options> [file...]\n\
%s {-f field-list,--fields=field-list} [-d delim] [-s] \n\
[--delimiter=delim] [--only-delimited] <options> [file...]\n\
Options: [--help] [--version]\n",
program_name, program_name, program_name);
exit (2);
}