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Diffstat (limited to 'node_modules/shelljs/src/tail.js')
-rw-r--r-- | node_modules/shelljs/src/tail.js | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/node_modules/shelljs/src/tail.js b/node_modules/shelljs/src/tail.js new file mode 100644 index 000000000..7ece654b1 --- /dev/null +++ b/node_modules/shelljs/src/tail.js @@ -0,0 +1,72 @@ +var common = require('./common'); +var fs = require('fs'); + +common.register('tail', _tail, { + canReceivePipe: true, + cmdOptions: { + 'n': 'numLines', + }, +}); + +//@ +//@ ### tail([{'-n': \<num\>},] file [, file ...]) +//@ ### tail([{'-n': \<num\>},] file_array) +//@ Available options: +//@ +//@ + `-n <num>`: Show the last `<num>` lines of the files +//@ +//@ Examples: +//@ +//@ ```javascript +//@ var str = tail({'-n': 1}, 'file*.txt'); +//@ var str = tail('file1', 'file2'); +//@ var str = tail(['file1', 'file2']); // same as above +//@ ``` +//@ +//@ Read the end of a file. +function _tail(options, files) { + var tail = []; + var pipe = common.readFromPipe(); + + if (!files && !pipe) common.error('no paths given'); + + var idx = 1; + if (options.numLines === true) { + idx = 2; + options.numLines = Number(arguments[1]); + } else if (options.numLines === false) { + options.numLines = 10; + } + options.numLines = -1 * Math.abs(options.numLines); + files = [].slice.call(arguments, idx); + + if (pipe) { + files.unshift('-'); + } + + var shouldAppendNewline = false; + files.forEach(function (file) { + if (!fs.existsSync(file) && file !== '-') { + common.error('no such file or directory: ' + file, { continue: true }); + return; + } + + var contents = file === '-' ? pipe : fs.readFileSync(file, 'utf8'); + + var lines = contents.split('\n'); + if (lines[lines.length - 1] === '') { + lines.pop(); + shouldAppendNewline = true; + } else { + shouldAppendNewline = false; + } + + tail = tail.concat(lines.slice(options.numLines)); + }); + + if (shouldAppendNewline) { + tail.push(''); // to add a trailing newline once we join + } + return tail.join('\n'); +} +module.exports = _tail; |