1/* vi: set sw=4 ts=4: */ 2/* fold -- wrap each input line to fit in specified width. 3 4 Written by David MacKenzie, djm@gnu.ai.mit.edu. 5 Copyright (C) 91, 1995-2002 Free Software Foundation, Inc. 6 7 Modified for busybox based on coreutils v 5.0 8 Copyright (C) 2003 Glenn McGrath <bug1@iinet.net.au> 9 10 Licensed under the GPL v2 or later, see the file LICENSE in this tarball. 11*/ 12 13#include "libbb.h" 14 15static unsigned long flags; 16#define FLAG_COUNT_BYTES 1 17#define FLAG_BREAK_SPACES 2 18#define FLAG_WIDTH 4 19 20/* Assuming the current column is COLUMN, return the column that 21 printing C will move the cursor to. 22 The first column is 0. */ 23 24static int adjust_column(int column, char c) 25{ 26 if (!(flags & FLAG_COUNT_BYTES)) { 27 if (c == '\b') { 28 if (column > 0) 29 column--; 30 } else if (c == '\r') 31 column = 0; 32 else if (c == '\t') 33 column = column + 8 - column % 8; 34 else /* if (isprint (c)) */ 35 column++; 36 } else 37 column++; 38 return column; 39} 40 41int fold_main(int argc, char **argv); 42int fold_main(int argc, char **argv) 43{ 44 char *line_out = NULL; 45 int allocated_out = 0; 46 char *w_opt; 47 int width = 80; 48 int i; 49 int errs = 0; 50 51 if (ENABLE_INCLUDE_SUSv2) { 52 /* Turn any numeric options into -w options. */ 53 for (i = 1; i < argc; i++) { 54 char const *a = argv[i]; 55 56 if (*a++ == '-') { 57 if (*a == '-' && !a[1]) 58 break; 59 if (isdigit(*a)) { 60 argv[i] = xasprintf("-w%s", a); 61 } 62 } 63 } 64 } 65 66 flags = getopt32(argv, "bsw:", &w_opt); 67 if (flags & FLAG_WIDTH) 68 width = xatoul_range(w_opt, 1, 10000); 69 70 argv += optind; 71 if (!*argv) { 72 *--argv = (char*)"-"; 73 } 74 75 do { 76 FILE *istream = fopen_or_warn_stdin(*argv); 77 int c; 78 int column = 0; /* Screen column where next char will go. */ 79 int offset_out = 0; /* Index in `line_out' for next char. */ 80 81 if (istream == NULL) { 82 errs |= EXIT_FAILURE; 83 continue; 84 } 85 86 while ((c = getc(istream)) != EOF) { 87 if (offset_out + 1 >= allocated_out) { 88 allocated_out += 1024; 89 line_out = xrealloc(line_out, allocated_out); 90 } 91 92 if (c == '\n') { 93 line_out[offset_out++] = c; 94 fwrite(line_out, sizeof(char), (size_t) offset_out, stdout); 95 column = offset_out = 0; 96 continue; 97 } 98 rescan: 99 column = adjust_column(column, c); 100 101 if (column > width) { 102 /* This character would make the line too long. 103 Print the line plus a newline, and make this character 104 start the next line. */ 105 if (flags & FLAG_BREAK_SPACES) { 106 /* Look for the last blank. */ 107 int logical_end; 108 109 for (logical_end = offset_out - 1; logical_end >= 0; logical_end--) { 110 if (isblank(line_out[logical_end])) { 111 break; 112 } 113 } 114 if (logical_end >= 0) { 115 /* Found a blank. Don't output the part after it. */ 116 logical_end++; 117 fwrite(line_out, sizeof(char), (size_t) logical_end, stdout); 118 putchar('\n'); 119 /* Move the remainder to the beginning of the next line. 120 The areas being copied here might overlap. */ 121 memmove(line_out, line_out + logical_end, offset_out - logical_end); 122 offset_out -= logical_end; 123 for (column = i = 0; i < offset_out; i++) { 124 column = adjust_column(column, line_out[i]); 125 } 126 goto rescan; 127 } 128 } else { 129 if (offset_out == 0) { 130 line_out[offset_out++] = c; 131 continue; 132 } 133 } 134 line_out[offset_out++] = '\n'; 135 fwrite(line_out, sizeof(char), (size_t) offset_out, stdout); 136 column = offset_out = 0; 137 goto rescan; 138 } 139 140 line_out[offset_out++] = c; 141 } 142 143 if (offset_out) { 144 fwrite(line_out, sizeof(char), (size_t) offset_out, stdout); 145 } 146 147 if (ferror(istream) || fclose_if_not_stdin(istream)) { 148 bb_perror_msg("%s", *argv); /* Avoid multibyte problems. */ 149 errs |= EXIT_FAILURE; 150 } 151 } while (*++argv); 152 153 fflush_stdout_and_exit(errs); 154} 155