]> mj.ucw.cz Git - xsv.git/blobdiff - xsv.c
Added two-pass code and --table format
[xsv.git] / xsv.c
diff --git a/xsv.c b/xsv.c
index 38f1fdeac88088859fae44f2835f080f971a4fbe..5bf4f01537a3d211d8575b3c3abd5b6609d42138 100644 (file)
--- a/xsv.c
+++ b/xsv.c
@@ -7,8 +7,11 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <stdarg.h>
 #include <getopt.h>
 
+#include <pcre.h>
+
 /*** Memory allocation ***/
 
 static void *xmalloc(size_t bytes)
@@ -21,6 +24,13 @@ static void *xmalloc(size_t bytes)
        return p;
 }
 
+static void *xmalloc_zero(size_t bytes)
+{
+       void *p = xmalloc(bytes);
+       memset(p, 0, bytes);
+       return p;
+}
+
 static void *xrealloc(void *old, size_t bytes)
 {
        void *p = realloc(old, bytes);
@@ -44,9 +54,12 @@ static void *xrealloc(void *old, size_t bytes)
                if (b->count >= b->max) name##_extend(b);                                       \
                return &b->start[b->count++];                                                   \
        }                                                                                       \
+       static inline type *name##_first(name##_t *b) { return b->start; }                      \
        static inline type *name##_nth(name##_t *b, int n) { return &b->start[n]; }             \
        // end
 
+DECLARE_BUF(intarray, int);
+
 /*** Formats and their parameters ***/
 
 enum format_id {
@@ -54,17 +67,40 @@ enum format_id {
        FORM_TSV,
        FORM_CSV,
        FORM_WS,
+       FORM_REGEX,
+       FORM_TMP,
+       FORM_TABLE,
 };
 
 struct format {
        enum format_id id;
        int fs;
        int quote;
+       int quiet;
        int (*read_line)(void);
        void (*write_line)(void);
+       int needs_two_passes;
+
+       // CSV backend:
+       int always_quote;
+
+       // WS backend:
+       int strict_ws;
+
+       // regex backend:
+       pcre *pcre;
+       pcre_extra *pcre_extra;
+
+       // Temporary file backend:
+       FILE *tmp_file;
+       intarray_t column_widths;
+
+       // Table backend:
+       int table_sep;
 };
 
 static struct format *in_format, *out_format;
+static int want_trim;
 
 struct field {
        int start_pos;
@@ -77,33 +113,66 @@ DECLARE_BUF(line, unsigned char);
 static fields_t in_fields, out_fields;
 static struct field *in_field;
 static line_t in_line;
+static int line_number;
 
-static void new_field(void)
+static void new_field(int pos)
 {
        in_field = fields_push(&in_fields);
-       in_field->start_pos = line_count(&in_line);
+       in_field->start_pos = pos;
        in_field->len = 0;
 }
 
-static void ensure_field(void)
+static void ensure_field(int pos)
 {
        if (!in_field)
-               new_field();
+               new_field(pos);
+}
+
+static void warn(struct format *fmt, char *msg, ...)
+{
+       if (!fmt->quiet) {
+               fprintf(stderr, "Warning at line %d: ", line_number);
+               va_list args;
+               va_start(args, msg);
+               vfprintf(stderr, args, msg);
+               va_end(args);
+               fputc('\n', stderr);
+       }
 }
 
+static int next_line(void)
+{
+       for (;;) {
+               int c = getchar();
+               if (c == '\r')
+                       continue;
+               if (c < 0)
+                       return !!line_count(&in_line);
+               if (c == '\n')
+                       return 1;
+               *line_push(&in_line) = c;
+       }
+}
+
+/*** CSV/TSV back-end */
+
 static int csv_read(void)
 {
        int quoted = 0;
-       // FIXME: Complain if closing quote is missing?
        for (;;) {
                int c = getchar();
+               int i = line_count(&in_line);
 restart:
-               if (c < 0)
-                       return !!fields_count(&in_fields);
                if (c == '\r')
                        continue;
-               if (c == '\n')
-                       return 1;
+               if (c < 0 || c == '\n') {
+                       if (quoted)
+                               warn(in_format, "Missing closing quote.");
+                       if (c < 0)
+                               return !!fields_count(&in_fields);
+                       else
+                               return 1;
+               }
                if (quoted) {
                        if (c == in_format->quote) {
                                c = getchar();
@@ -118,30 +187,34 @@ restart:
                        quoted = 1;
                        continue;
                } else if (c == in_format->fs && !quoted) {
-                       ensure_field();
-                       new_field();
+                       ensure_field(i);
+                       new_field(i);
                        continue;
                }
-               ensure_field();
+               ensure_field(i);
                *line_push(&in_line) = c;
                in_field->len++;
        }
 }
 
+static int is_ws(int c)
+{
+       return (c == ' ' || c == '\t' || c == '\f');
+}
+
 static void csv_write(void)
 {
-       unsigned char *line = line_nth(&in_line, 0);
+       unsigned char *line = line_first(&in_line);
        int n = fields_count(&out_fields);
        for (int i=0; i<n; i++) {
                struct field *f = fields_nth(&out_fields, i);
                int need_quotes = 0;
                if (out_format->quote >= 0) {
-                       for (int j=0; j < f->len; j++) {
+                       need_quotes = out_format->always_quote;
+                       for (int j=0; !need_quotes && j < f->len; j++) {
                                int c = line[f->start_pos + j];
-                               if (c == out_format->fs || c == out_format->quote) {
+                               if (c == out_format->fs || c == out_format->quote)
                                        need_quotes = 1;
-                                       break;
-                               }
                        }
                }
                if (i)
@@ -150,6 +223,8 @@ static void csv_write(void)
                        putchar(out_format->quote);
                for (int j=0; j < f->len; j++) {
                        int c = line[f->start_pos + j];
+                       if (c == out_format->fs && !need_quotes)
+                               warn(out_format, "Field separator found inside field and quoting is turned off.");
                        if (c == out_format->quote)
                                putchar(c);
                        putchar(c);
@@ -160,29 +235,187 @@ static void csv_write(void)
        putchar('\n');
 }
 
+/*** White-space back-end ***/
+
 static int ws_read(void)
 {
+       if (!next_line())
+               return 0;
+
+       unsigned char *line = line_first(&in_line);
+       int n = line_count(&in_line);
+       if (!n)
+               return 1;
+
        int ws = 0;
-       for (;;) {
-               int c = getchar();
-               if (c < 0)
-                       return !!fields_count(&in_fields);
-               if (c == '\r')
-                       continue;
-               if (c == '\n')
-                       return 1;
-               if (c == ' ' || c == '\t' || c == '\f') {
-                       ensure_field();
-                       if (!ws)
-                               new_field();
+       new_field(0);
+       for (int i=0; i<n; i++) {
+               int c = line[i];
+               if (is_ws(c)) {
                        ws++;
                } else {
-                       ensure_field();
-                       *line_push(&in_line) = c;
+                       if (ws) {
+                               if (!in_field->start_pos &&
+                                   !in_field->len &&
+                                   !in_format->strict_ws)
+                                       in_field->start_pos = i;
+                               else
+                                       new_field(i);
+                               ws = 0;
+                       }
                        in_field->len++;
-                       ws = 0;
                }
        }
+
+       if (ws && in_format->strict_ws)
+               new_field(n);
+       return 1;
+}
+
+/*** Regex back-end ***/
+
+static const char *regex_set(struct format *f, char *rx)
+{
+       const char *err;
+       int errpos;
+       f->pcre = pcre_compile(rx, PCRE_DOLLAR_ENDONLY, &err, &errpos, NULL);
+       if (!f->pcre)
+               return err;
+
+       f->pcre_extra = pcre_study(f->pcre, 0, &err);
+       if (!f->pcre_extra)
+               return err;
+
+       return NULL;
+}
+
+static int regex_read(void)
+{
+       if (!next_line())
+               return 0;
+
+       unsigned char *c = line_first(&in_line);
+       int n = line_count(&in_line);
+       if (!n)
+               return 1;
+
+       int i = 0;
+       for (;;) {
+               int ovec[3];
+               int sep = pcre_exec(in_format->pcre, in_format->pcre_extra, (char *) c, n, i, 0, ovec, 3);
+               if (sep < 0) {
+                       if (sep != PCRE_ERROR_NOMATCH)
+                               warn(in_format, "PCRE matching error %d", sep);
+                       // No further occurrence of the separator: the rest is a single field
+                       new_field(i);
+                       in_field->len = n - i;
+                       return 1;
+               }
+               new_field(i);
+               in_field->len = ovec[0] - i;
+               i = ovec[1];
+       }
+}
+
+/*** Table back-end ***/
+
+static void table_write(void)
+{
+       for (int i = 0; i < fields_count(&in_fields); i++) {
+               if (i)
+                       printf("%*s", out_format->table_sep, "");
+               struct field *f = fields_nth(&in_fields, i);
+               int w = *intarray_nth(&in_format->column_widths, i);
+               if (f->len > w) {
+                       warn(out_format, "Internal error: Wrongly calculated column width (%d > %d)", f->len, w);
+                       w = f->len;
+               }
+               int j = 0;
+               unsigned char *p = line_nth(&in_line, f->start_pos);
+               while (j < f->len) {
+                       putchar(*p++);
+                       j++;
+               }
+               while (j < w) {
+                       putchar(' ');
+                       j++;
+               }
+       }
+       putchar('\n');
+}
+
+/*** Temporary file back-end ***/
+
+static int tmp_read(void)
+{
+       FILE *tf = in_format->tmp_file;
+
+       for (;;) {
+               int c = fgetc(tf);
+               if (c < 0)
+                       return 0;
+               if (c == 0xff)
+                       return 1;
+               if (c == 0xfe) {
+                       c = fgetc(tf);
+                       c = (c << 8) | fgetc(tf);
+                       c = (c << 8) | fgetc(tf);
+                       c = (c << 8) | fgetc(tf);
+               }
+               new_field(line_count(&in_line));
+               in_field->len = c;
+               while (c--) {
+                       int x = fgetc(tf);
+                       if (x < 0) {
+                               warn(in_format, "Truncated temporary file");
+                               return 0;
+                       }
+                       *line_push(&in_line) = x;
+               }
+       }
+}
+
+static void tmp_write(void)
+{
+       FILE *tf = out_format->tmp_file;
+
+       for (int i = 0; i < fields_count(&in_fields); i++) {
+               struct field *f = fields_nth(&in_fields, i);
+               if (f->len < 0xfe)
+                       fputc(f->len, tf);
+               else {
+                       fputc(0xfe, tf);
+                       fputc((f->len >> 24) & 0xff, tf);
+                       fputc((f->len >> 16) & 0xff, tf);
+                       fputc((f->len >> 8) & 0xff, tf);
+                       fputc(f->len & 0xff, tf);
+               }
+
+               unsigned char *p = line_nth(&in_line, f->start_pos);
+               for (int j = 0; j < f->len; j++)
+                       fputc(*p++, tf);
+
+               intarray_t *w = &out_format->column_widths;
+               while (i >= intarray_count(w))
+                       *intarray_push(w) = 0;
+               if (*intarray_nth(w, i) < f->len)
+                       *intarray_nth(w, i) = f->len;
+       }
+       fputc(0xff, tf);
+}
+
+/*** Transforms ***/
+
+static void trim_fields(void)
+{
+       unsigned char *line = line_first(&in_line);
+       for (int i = 0; i < fields_count(&in_fields); i++) {
+               struct field *f = fields_nth(&in_fields, i);
+               while (f->len && is_ws(line[f->start_pos]))
+                       f->start_pos++, f->len--;
+               while (f->len && is_ws(line[f->start_pos + f->len - 1]))
+                       f->len--;
+       }
 }
 
 /*** Field selection ***/
@@ -237,6 +470,50 @@ static void select_fields(void)
        }
 }
 
+/*** Processing of files ***/
+
+static void one_pass(void)
+{
+       line_number = 0;
+       for (;;) {
+               line_number++;
+               fields_reset(&in_fields);
+               line_reset(&in_line);
+               in_field = NULL;
+               if (!in_format->read_line())
+                       break;
+
+               if (want_trim)
+                       trim_fields();
+
+               fields_reset(&out_fields);
+               select_fields();
+
+               out_format->write_line();
+       }
+}
+
+static void two_pass(void)
+{
+       struct format *final_format = out_format;
+
+       // Pass 1: Set up writer of intermediate format
+       out_format = xmalloc_zero(sizeof(*out_format));
+       out_format->id = FORM_TMP;
+       out_format->read_line = tmp_read;
+       out_format->write_line = tmp_write;
+       out_format->tmp_file = tmpfile();
+       intarray_init(&out_format->column_widths);
+       one_pass();
+
+       // Pass 2: Set up reader of intermediate format
+       in_format = out_format;
+       rewind(in_format->tmp_file);
+       out_format = final_format;
+       one_pass();
+       fclose(in_format->tmp_file);
+}
+
 /*** Parsing of arguments ***/
 
 static void usage(void)
@@ -248,33 +525,56 @@ Formats:\n\
 -t, --tsv              TAB-separated values (default)\n\
 -c, --csv              Comma-separated values\n\
 -w, --ws               Values separated by arbitrary whitespace\n\
+-W, --strict-ws                Like --ws, but recognize empty columns at start/end\n\
+-r, --regex=<rx>       Separator given by Perl regular expression (input only)\n\
+    --table            Format a table (output only)\n\
 \n\
 Format parameters:\n\
--d, --fs=<char>        Delimiter of fields\n\
+-d, --fs=<char>                Delimiter of fields\n\
+-q, --quiet            Do not show warnings\n\
+    --always-quote     Put quotes around all fields (CSV output only)\n\
+    --table-sep=<n>    Separate table columns by <n> spaces (default: 2)\n\
 \n\
 Other options:\n\
-(so far none)\n\
+    --trim             Trim leading and trailing whitespaces in fields\n\
 ");
        exit(0);
 }
 
-static void bad_args(char *msg)
+static void bad_args(const char *msg, ...)
 {
-       if (msg)
-               fprintf(stderr, "xsv: %s\n", msg);
+       if (msg) {
+               va_list args;
+               va_start(args, msg);
+               fprintf(stderr, "xsv: ");
+               vfprintf(stderr, msg, args);
+               fputc('\n', stderr);
+               va_end(args);
+       }
        fprintf(stderr, "Try `xsv --help' for more information.\n");
        exit(1);
 }
 
-static const char short_options[] = "cd:tw";
+static const char short_options[] = "cd:qr:twW";
 
 enum long_options {
        OPT_HELP = 256,
+       OPT_TRIM,
+       OPT_ALWAYS_QUOTE,
+       OPT_TABLE,
+       OPT_TABLE_SEP,
 };
 
 static const struct option long_options[] = {
+       { "always-quote",       0,      NULL,   OPT_ALWAYS_QUOTE },
        { "csv",                0,      NULL,   'c' },
        { "fs",                 1,      NULL,   'd' },
+       { "quiet",              0,      NULL,   'q' },
+       { "regex",              1,      NULL,   'r' },
+       { "strict-ws",          0,      NULL,   'W' },
+       { "table",              0,      NULL,   OPT_TABLE },
+       { "table-sep",          1,      NULL,   OPT_TABLE_SEP },
+       { "trim",               0,      NULL,   OPT_TRIM },
        { "tsv",                0,      NULL,   't' },
        { "ws",                 0,      NULL,   'w' },
        { "help",               0,      NULL,   OPT_HELP },
@@ -283,8 +583,7 @@ static const struct option long_options[] = {
 
 static void set_format(int format_id)
 {
-       struct format *f = xmalloc(sizeof(*f));
-       memset(f, 0, sizeof(*f));
+       struct format *f = xmalloc_zero(sizeof(*f));
        f->id = format_id;
 
        switch (format_id) {
@@ -306,6 +605,14 @@ static void set_format(int format_id)
                        f->read_line = ws_read;
                        f->write_line = csv_write;
                        break;
+               case FORM_REGEX:
+                       f->read_line = regex_read;
+                       break;
+               case FORM_TABLE:
+                       f->write_line = table_write;
+                       f->needs_two_passes = 1;
+                       f->table_sep = 2;
+                       break;
        }
 
        if (!in_format)
@@ -313,7 +620,7 @@ static void set_format(int format_id)
        else if (!out_format)
                out_format = f;
        else
-               bad_args("At most two format may be given.");
+               bad_args("At most two formats may be given.");
 }
 
 static struct format *current_format(void)
@@ -329,6 +636,7 @@ static struct format *current_format(void)
 int main(int argc, char **argv)
 {
        int opt;
+       const char *err;
 
        while ((opt = getopt_long(argc, argv, short_options, long_options, NULL)) >= 0)
                switch (opt) {
@@ -341,14 +649,41 @@ int main(int argc, char **argv)
                                else
                                        bad_args("No field delimiter given.");
                                break;
+                       case 'q':
+                               current_format()->quiet = 1;
+                               break;
+                       case 'r':
+                               set_format(FORM_REGEX);
+                               err = regex_set(current_format(), optarg);
+                               if (err)
+                                       bad_args("Error compiling regex: %s", err);
+                               break;
                        case 't':
                                set_format(FORM_TSV);
                                break;
                        case 'w':
                                set_format(FORM_WS);
                                break;
+                       case 'W':
+                               set_format(FORM_WS);
+                               current_format()->strict_ws = 1;
+                               break;
+                       case OPT_ALWAYS_QUOTE:
+                               if (current_format()->id != FORM_CSV)
+                                       bad_args("--always-quote makes sense only for CSV.");
+                               current_format()->always_quote = 1;
+                               break;
                        case OPT_HELP:
                                usage();
+                       case OPT_TRIM:
+                               want_trim = 1;
+                               break;
+                       case OPT_TABLE:
+                               set_format(FORM_TABLE);
+                               break;
+                       case OPT_TABLE_SEP:
+                               current_format()->table_sep = atoi(optarg);
+                               break;
                        default:
                                bad_args(NULL);
                }
@@ -356,9 +691,13 @@ int main(int argc, char **argv)
        current_format();
        if (!out_format)
                out_format = in_format;
+       if (!in_format->read_line)
+               bad_args("Write-only format selected for input.");
+       if (!out_format->write_line)
+               bad_args("Read-only format selected for output.");
 
        for (int i = optind; i < argc; i++) {
-               char *err = parse_selector(argv[i]);
+               err = parse_selector(argv[i]);
                if (err)
                        bad_args(err);
        }
@@ -368,18 +707,9 @@ int main(int argc, char **argv)
        fields_init(&out_fields);
        line_init(&in_line);
 
-       for (;;) {
-               fields_reset(&in_fields);
-               line_reset(&in_line);
-               in_field = NULL;
-               if (!in_format->read_line())
-                       break;
-
-               fields_reset(&out_fields);
-               select_fields();
-
-               out_format->write_line();
-       }
-
+       if (out_format->needs_two_passes)
+               two_pass();
+       else
+               one_pass();
        return 0;
 }