03-02-2006
You're right about closing the file, my bad. However - 256 appears arbitrary. It is not.
Whatever file record length he/she expects, best practice dictates using a variable that is decalred to be significantly larger.
However - and don't get me going on this - picking lengths that are just one char longer than the record leads to trouble in production systems, if the program deals with data derived from any external source. And the memory savings is not worth the cost of debugging and fixing it later on, because some users did not follow procedures.
If you're worried about memory, which, within reason, is basically not merited except in embedded systems or realtime processing, check your requirements. I seldom see - "must run in less than 10MB of memory" - as a stipulated requirement. It's the same issue as using floats instead of doubles because it "saves memory" or "is faster".
The "is faster" is debatable, and is hardware dependant, plus floats are often promoted to doubles. The "saves memory" is usually correct except that what you gain is not worth what you lose - 9 digits of precision.
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RLAM(1) General Commands Manual RLAM(1)
NAME
rlam - laminate records from multiple files
SYNOPSIS
rlam [ -tS ][ -u ][ -iaN | -ifN | -idN | -iiN | -iwN | -ibN ] input1 input2 ..
DESCRIPTION
Rlam simply joins records (or lines) from multiple inputs, separating them with the given string (TAB by default). Different separators
may be given for different files by specifying additional -t options in between each file name. Note that there is no space between this
option and its argument. If none of the input files uses an ASCII separator, then no end-of-line character will be printed, either.
An input is either a stream or a command. Commands are given in quotes, and begin with an exclamantion point ('!'). If the inputs do not
have the same number of lines, then shorter files will stop contributing to the output as they run out.
The -ia option may be used to specify ASCII input (the default), or the -if option may be used to indicated binary IEEE 32-bit floats on
input. Similarly, the -id and -ii options may be used to indicate binary 64-bit doubles or integer words, respectively. The -iw option
specifies 2-byte short words, and the -ib option specifies bytes. If a number is immediately follows any of these options, then it indi-
cates that multiple such values are expected for each record. For example, -if3 indicates three floats per input record for the next named
input. In the case of the -ia option, no number indicates one line per input record, and numbers greater than zero indicate that many
characters exactly per record. For binary input formts, no number implies one value per record. For anything other than EOL-separated
input, the default tab separator is reset to the empty string.
A hyphen ('-') by itself can be used to indicate the standard input, and may appear multiple times. The -u option forces output after each
record (i.e., one run through inputs).
EXAMPLE
To join files output1 and output2, separated by a comma:
rlam -t, output1 output2
To join a file with line numbers (starting at 0) and its reverse:
cnt `wc -l < lam.c` | rlam - -t: lam.c -t '!tail -r lam.c'
To join four data files, each having three doubles per record:
rlam -id3 file1.dbl file2.dbl file3.dbl file4.dbl > combined.dbl
AUTHOR
Greg Ward
SEE ALSO
cnt(1), histo(1), neaten(1), rcalc(1), tabfunc(1), total(1)
RADIANCE
7/8/97 RLAM(1)