diff options
Diffstat (limited to 'coreutils/fold.c')
-rw-r--r-- | coreutils/fold.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/coreutils/fold.c b/coreutils/fold.c new file mode 100644 index 0000000..e2a30d5 --- /dev/null +++ b/coreutils/fold.c @@ -0,0 +1,151 @@ +/* vi: set sw=4 ts=4: */ +/* fold -- wrap each input line to fit in specified width. + + Written by David MacKenzie, djm@gnu.ai.mit.edu. + Copyright (C) 91, 1995-2002 Free Software Foundation, Inc. + + Modified for busybox based on coreutils v 5.0 + Copyright (C) 2003 Glenn McGrath + + Licensed under the GPL v2 or later, see the file LICENSE in this tarball. +*/ + +#include "libbb.h" + +/* Must match getopt32 call */ +#define FLAG_COUNT_BYTES 1 +#define FLAG_BREAK_SPACES 2 +#define FLAG_WIDTH 4 + +/* Assuming the current column is COLUMN, return the column that + printing C will move the cursor to. + The first column is 0. */ +static int adjust_column(int column, char c) +{ + if (!(option_mask32 & FLAG_COUNT_BYTES)) { + if (c == '\b') { + if (column > 0) + column--; + } else if (c == '\r') + column = 0; + else if (c == '\t') + column = column + 8 - column % 8; + else /* if (isprint (c)) */ + column++; + } else + column++; + return column; +} + +int fold_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int fold_main(int argc, char **argv) +{ + char *line_out = NULL; + int allocated_out = 0; + char *w_opt; + int width = 80; + int i; + int errs = 0; + + if (ENABLE_INCLUDE_SUSv2) { + /* Turn any numeric options into -w options. */ + for (i = 1; i < argc; i++) { + char const *a = argv[i]; + + if (*a++ == '-') { + if (*a == '-' && !a[1]) /* "--" */ + break; + if (isdigit(*a)) + argv[i] = xasprintf("-w%s", a); + } + } + } + + getopt32(argv, "bsw:", &w_opt); + if (option_mask32 & FLAG_WIDTH) + width = xatoul_range(w_opt, 1, 10000); + + argv += optind; + if (!*argv) + *--argv = (char*)"-"; + + do { + FILE *istream = fopen_or_warn_stdin(*argv); + int c; + int column = 0; /* Screen column where next char will go. */ + int offset_out = 0; /* Index in 'line_out' for next char. */ + + if (istream == NULL) { + errs |= EXIT_FAILURE; + continue; + } + + while ((c = getc(istream)) != EOF) { + if (offset_out + 1 >= allocated_out) { + allocated_out += 1024; + line_out = xrealloc(line_out, allocated_out); + } + + if (c == '\n') { + line_out[offset_out++] = c; + fwrite(line_out, sizeof(char), (size_t) offset_out, stdout); + column = offset_out = 0; + continue; + } + rescan: + column = adjust_column(column, c); + + if (column > width) { + /* This character would make the line too long. + Print the line plus a newline, and make this character + start the next line. */ + if (option_mask32 & FLAG_BREAK_SPACES) { + /* Look for the last blank. */ + int logical_end; + + for (logical_end = offset_out - 1; logical_end >= 0; logical_end--) { + if (isblank(line_out[logical_end])) { + break; + } + } + if (logical_end >= 0) { + /* Found a blank. Don't output the part after it. */ + logical_end++; + fwrite(line_out, sizeof(char), (size_t) logical_end, stdout); + bb_putchar('\n'); + /* Move the remainder to the beginning of the next line. + The areas being copied here might overlap. */ + memmove(line_out, line_out + logical_end, offset_out - logical_end); + offset_out -= logical_end; + for (column = i = 0; i < offset_out; i++) { + column = adjust_column(column, line_out[i]); + } + goto rescan; + } + } else { + if (offset_out == 0) { + line_out[offset_out++] = c; + continue; + } + } + line_out[offset_out++] = '\n'; + fwrite(line_out, sizeof(char), (size_t) offset_out, stdout); + column = offset_out = 0; + goto rescan; + } + + line_out[offset_out++] = c; + } + + if (offset_out) { + fwrite(line_out, sizeof(char), (size_t) offset_out, stdout); + } + + if (fclose_if_not_stdin(istream)) { + bb_simple_perror_msg(*argv); /* Avoid multibyte problems. */ + errs |= EXIT_FAILURE; + } + } while (*++argv); + + fflush_stdout_and_exit(errs); +} |