ubuntu-buildroot/output/build/host-gawk-5.2.0/awklib/eg/prog/cut.awk

138 lines
3.6 KiB
Awk

# cut.awk --- implement cut in awk
#
# Arnold Robbins, arnold@skeeve.com, Public Domain
# May 1993
# Options:
# -c list Cut characters
# -f list Cut fields
# -d c Field delimiter character
#
# -s Suppress lines without the delimiter
#
# Requires getopt() and join() library functions
function usage()
{
print("usage: cut [-f list] [-d c] [-s] [files...]") > "/dev/stderr"
print(" cut [-c list] [files...]") > "/dev/stderr"
exit 1
}
BEGIN {
FS = "\t" # default
OFS = FS
while ((c = getopt(ARGC, ARGV, "sf:c:d:")) != -1) {
if (c == "f") {
by_fields = 1
fieldlist = Optarg
} else if (c == "c") {
by_chars = 1
fieldlist = Optarg
OFS = ""
} else if (c == "d") {
if (length(Optarg) > 1) {
printf("cut: using first character of %s" \
" for delimiter\n", Optarg) > "/dev/stderr"
Optarg = substr(Optarg, 1, 1)
}
fs = FS = Optarg
OFS = FS
if (FS == " ") # defeat awk semantics
FS = "[ ]"
} else if (c == "s")
suppress = 1
else
usage()
}
# Clear out options
for (i = 1; i < Optind; i++)
ARGV[i] = ""
if (by_fields && by_chars)
usage()
if (by_fields == 0 && by_chars == 0)
by_fields = 1 # default
if (fieldlist == "") {
print "cut: needs list for -c or -f" > "/dev/stderr"
exit 1
}
if (by_fields)
set_fieldlist()
else
set_charlist()
}
function set_fieldlist( n, m, i, j, k, f, g)
{
n = split(fieldlist, f, ",")
j = 1 # index in flist
for (i = 1; i <= n; i++) {
if (index(f[i], "-") != 0) { # a range
m = split(f[i], g, "-")
if (m != 2 || g[1] >= g[2]) {
printf("cut: bad field list: %s\n",
f[i]) > "/dev/stderr"
exit 1
}
for (k = g[1]; k <= g[2]; k++)
flist[j++] = k
} else
flist[j++] = f[i]
}
nfields = j - 1
}
function set_charlist( field, i, j, f, g, n, m, t,
filler, last, len)
{
field = 1 # count total fields
n = split(fieldlist, f, ",")
j = 1 # index in flist
for (i = 1; i <= n; i++) {
if (index(f[i], "-") != 0) { # range
m = split(f[i], g, "-")
if (m != 2 || g[1] >= g[2]) {
printf("cut: bad character list: %s\n",
f[i]) > "/dev/stderr"
exit 1
}
len = g[2] - g[1] + 1
if (g[1] > 1) # compute length of filler
filler = g[1] - last - 1
else
filler = 0
if (filler)
t[field++] = filler
t[field++] = len # length of field
last = g[2]
flist[j++] = field - 1
} else {
if (f[i] > 1)
filler = f[i] - last - 1
else
filler = 0
if (filler)
t[field++] = filler
t[field++] = 1
last = f[i]
flist[j++] = field - 1
}
}
FIELDWIDTHS = join(t, 1, field - 1)
nfields = j - 1
}
{
if (by_fields && suppress && index($0, fs) == 0)
next
for (i = 1; i <= nfields; i++) {
if ($flist[i] != "") {
printf "%s", $flist[i]
if (i < nfields && $flist[i+1] != "")
printf "%s", OFS
}
}
print ""
}